- thin (adj.)
- Old English þynne "narrow, lean, scanty," from Proto-Germanic *thunnuz, *thunw- (cf. West Frisian ten, Middle Low German dunne, Dutch dun, Old High German dunni, German dünn, Old Norse þunnr), from PIE *tnus-, *tnwi-, from weak grade of root *ten- "stretch" (cf. Latin tenuis "thin, slender;" see tenet).
These our actors ... were all Spirits, and Are melted into Ayre, into thin Ayre. [Shakespeare, "The Tempest," IV.i.150, 1610]
Thin-skinned is attested from 1590s; the figurative sense of "touchy" is from 1670s.
- thin (v.)
- Old English þynnian "to make thin" (cf. German dünnen, Dutch dunnen), from thin (adj.). Intransitive sense of "to become less numerous" is attested from 1743; that of "to become thinner" is recorded from 1804. Related: Thinned; thinning.