Webster's Revised Unabridged Dictionary · 1913

Thin

Thin , adjective

[Old English thinne, thenne, thunne, Anglo-Saxon þynne; akin to Dutch dun, German dunn, Old High German dunni, Icelandic þunnr, Swedish tunn, Danish tynd, Gael. & Ir. tana, Welsh teneu, Latin tenuis, Greek {not transcribed} (in comp.) stretched out, {not transcribed} stretched, stretched out, long, Sanskrit tanu thin, slender; also to Anglo-Saxon {not transcribed}enian to extend, German dehnen, Icelandic {not transcribed}enja, Gothic {not transcribed}anjan (in comp.), Latin tendere to stretch, tenere to hold, Greek {not transcribed} to stretch, Sanskrit tan. r51 & 237. Compare Attenuate, Dance, Tempt, Tenable, Tend to move, Tenous, Thunder, Tone.]

1.
Having little thickness or extent from one surface to its opposite; as, a thin plate of metal; thin paper; a thin board; a thin covering.
2.
Rare; not dense or thick; -- applied to fluids or soft mixtures; as, thin blood; thin broth; thin air. — Shakespeare
In the day, when the air is more thin. — Bacon
Satan, bowing low His gray dissimulation, disappeared, Into thin air diffused. — Milton
3.
Not close; not crowded; not filling the space; not having the individuals of which the thing is composed in a close or compact state; hence, not abundant; as, the trees of a forest are thin; the corn or grass is thin.
Ferrara is very large, but extremely thin of people. — Addison
4.
Not full or well grown; wanting in plumpness.
Seven thin ears... blasted with the east wind. — Gen. xli. 6
5.
Not stout; slim; slender; lean; gaunt; as, a person becomes thin by disease.
6.
Wanting in body or volume; small; feeble; not full.
Thin, hollow sounds, and lamentable screams. — Dryden
7.
Slight; small; slender; flimsy; wanting substance or depth or force; superficial; inadequate; not sufficient for a covering; as, a thin disguise.
My tale is done, for my wit is but thin. — Chaucer

Thin is used in the formation of compounds which are mostly self-explaining; as, thin-faced, thin-lipped, thin-peopled, thin-shelled, and the like.

Collocations (1)
Thin section , See under Section.

Thin , adverb

Not thickly or closely; in a seattered state; as, seed sown thin.
Spain is thin sown of people. — Bacon

Thin , transitive verb

[Compare Anglo-Saxon geþynnian.]

To make thin (in any of the senses of the adjective).

Thin , intransitive verb

To grow or become thin; -- used with some adverbs, as out, away, etc.; as, geological strata thin out, i. e., gradually diminish in thickness until they disappear.