26 Adjectives That Start With X
X is the smallest letter in English, and almost everything in it arrived from Greek. Four roots carry nearly the whole letter: xero- for dry, xylo- for wood, xantho- for yellow and xeno- for foreign or strange. Learn those four and most of this page decodes itself.
This page lists 26 adjectives that start with X, each with its meaning and a phrase showing it in use. Every one was checked for an adjective entry of its own in Merriam-Webster or Oxford, by reading the part-of-speech markup rather than trusting the page to load.
Two things are worth knowing before you start. First, this is a verified count and not a complete one: X is deep in the unabridged dictionary and the checking stopped before the letter did, so there are more. Second, Oxford Learner’s carries only 2 X adjectives in total — xenophobic and x-rated. Every other word here rests on Merriam-Webster alone, and 3 of them only on its medical dictionary, which their entries say.
Three words that a longer list would have included are deliberately left out. Xanthochroid, xanthochroic and xanthochroous are real Merriam-Webster entries, and all three belong to the same nineteenth-century racial taxonomy: xanthochroid is defined by pointing at the xanthochroi, Huxley’s category for fair-skinned, light-haired peoples, and the other two turn on the same yellowish-skin-and-fair-hair description. They are artifacts of race science rather than words anyone needs, and a vocabulary page is not the place to keep them in circulation.
All 26 adjectives at a glance
Every word on this page in one block. Each is defined further down.
X-linked, X-rated, xanthic, xanthochromic, xanthomatous, xanthous, xenial, xenogeneic, xenomorphic, xenophobic, xenoplastic, xerarch, xeric, xerographic, xeromorphic, xerophilous, xerophobous, xerophytic, xerothermic, xiphophyllous, xylographic, xyloid, xylophagous, xylophilous, xylotomic, xylotomous
Dryness and water
The xero- family, and the most useful part of the letter. If you garden or read plant labels you have met xeric and xerophytic already — xeriscaping is the reason xeric escaped botany into ordinary use.
| Adjective | What it means |
|---|---|
| xeric | needing, or marked by, only a small amount of moisture (a xeric habitat) |
| xeromorphic | of a plant, built structurally to survive dry conditions (xeromorphic leaves) |
| xerophilous | thriving in a dry place, and suited to one (xerophilous mosses) |
| xerophobous | of a plant, poorly able to withstand drought (xerophobous species) |
| xerophytic | of a plant, adapted to live on very little water (xerophytic cacti) |
| xerothermic | marked by heat together with dryness; suited to a hot dry place (a xerothermic period) |
Wood and making
The xylo- family. Xylophagous is the one with a life outside specialist writing: it is the standard word in pest control and museum conservation for anything that eats wood.
| Adjective | What it means |
|---|---|
| xylographic | of or relating to xylography, the art of engraving on wood (a xylographic print) |
| xyloid | resembling wood in quality or nature (a xyloid texture) |
| xylophagous | feeding on wood, or living in it (xylophagous beetles) |
| xylophilous | growing or living in or on wood (xylophilous fungi) |
| xylotomic | concerning xylotomy, the preparing of wood sections for study under a microscope (xylotomic analysis) |
| xylotomous | able to bore or cut wood, said of an insect (a xylotomous larva) |
Science and nature
A mixed section: two xeno- words meaning foreign or strange, two xero- ones, and a sword-shaped leaf. Read xenomorphic‘s entry before using it — it is about mineral grains, not the creature from the films.
| Adjective | What it means |
|---|---|
| xenogeneic | taken from, or belonging to, a different species (a xenogeneic graft) |
| xenomorphic | of a mineral grain, having a shape other than its own crystal form because neighbouring grains grew into the space first (xenomorphic grains) |
| xerarch | of a sequence of plant communities, developing in a dry place (a xerarch succession) |
| xerographic | of or produced by xerography, the dry copying process behind the photocopier (a xerographic print) |
| xiphophyllous | having leaves shaped like a sword (a xiphophyllous plant) |
Medicine and the body
The clinical corner, and the part of this page a reader is most likely to meet in writing about themselves. X-linked is the one to know — it turns up in any account of haemophilia, colour blindness or Duchenne muscular dystrophy.
| Adjective | What it means |
|---|---|
| X-linked | carried on the X chromosome, or passed on by a gene that sits there (an X-linked disorder) |
| xanthochromic | yellowish in discoloration, as fluid drawn from the spine can be after a bleed (xanthochromic fluid) [medical dictionary only] |
| xanthomatous | of or marked by a xanthoma, a fatty yellow deposit under the skin (xanthomatous lesions) [medical dictionary only] |
| xenoplastic | occurring between individuals that are only distantly related (a xenoplastic transplant) [medical dictionary only] |
Colour and appearance
The xantho- family, meaning yellow. A small section, because the three other members of it are the race-science terms the introduction explains are left out.
| Adjective | What it means |
|---|---|
| xanthic | tending toward yellow in colour; of a flower, tinged with yellow (a xanthic tinge) |
| xanthous | having yellowish, red, auburn or brown hair; also marked by yellow colouring (xanthous plumage) |
People and society
Two words, and they could hardly be further apart: xenial is the ancient Greek bond of hospitality between host and guest, and xenophobic is the fear of the same stranger. Both are built on xenos.
| Adjective | What it means |
|---|---|
| xenial | concerning hospitality, and the bond between a host and a guest (the xenial bond) |
| xenophobic | feeling or showing dislike or fear of people from other countries (xenophobic rhetoric) [disapproving] |
Everyday
One word, which tells you most of what you need to know about this letter.
| Adjective | What it means |
|---|---|
| X-rated | restricted to adult viewers because of sexual or violent content (an X-rated film) [especially of a film] |
Using them in a sentence
A list is only half the job. These show the words carrying weight rather than sitting decoratively in front of a noun.
- The border was planted with xerophytic shrubs, because nothing else survived the summer.
- Conservators found the frame riddled by something xylophagous.
- Haemophilia is X-linked, which is why it appears so much more often in boys.
- The rock was described as xenomorphic: the grains never had room to form properly.
- Greek hospitality was a xenial obligation, not a courtesy.
- The pigment was faintly xanthic, somewhere between cream and old ivory.
Words people get wrong
| Pair | The difference that matters |
|---|---|
| xeric / xerophytic | The dictionaries record an old quarrel here. Merriam-Webster’s note at xeric recounts that in 1926 specialists writing in Ecology proposed xeric as a general term covering plants and animals alike, and suggested xerophytic be abandoned as useless and misleading — while the Ecological Society of America thought xeric itself undesirable and preferred plain arid. Enough scientists ignored both rulings that all three words survive, which is why this page carries two of them. |
| xenomorphic / xenogeneic | Both begin with xeno-, foreign, and neither means what a reader expects. Xenomorphic is a petrology term for a mineral grain that never took its own crystal shape because its neighbours grew into the space first — it has nothing whatever to do with the creature from Alien, which is where almost everyone meets the word. Xenogeneic is the biology one: taken from a different species, as in a xenogeneic graft. |
| xanthic / xanthous | Two yellows from the same Greek root, applied to different things. Xanthic is a tint of yellow in a thing — Merriam-Webster scopes one sense to flowers, and it also has a chemistry life in xanthic acid. Xanthous is used of hair colour, and its history is close enough to the race-science words this page leaves out that it is worth using carefully. |
| xenophobic / x-rated | Not a confusion, but the pair worth naming: these are the only two X adjectives Oxford Learner’s carries at all. Oxford marks xenophobic disapproving, and scopes x-rated especially to films. Every other word on this page is Merriam-Webster’s alone, which is the plainest measure of how small this letter is in ordinary English. |
Related guides
- Adjectives for science — where most of this letter would be at home.
- Adjectives for space — a neighbouring vocabulary, and a much larger one.
- Adjectives for weird — for what xenomorphic is usually reached for by mistake.
- Adjectives for colours — where the xantho- words have plainer company.
- Adjectives that start with W — the letter before, and roughly two hundred times the size.
- Adjectives that start with Y — the other small letter, and a friendlier one.
Checked against Merriam-Webster, the Chicago Manual of Style and the AP Stylebook. Spotted an error? Tell us — see our editorial policy.
