a formative of sbs. a. from verbs; in some words, as bath, birth, death, math, oath, OTeut., repr. various Indo-Eur. suffixes, as -tos, -tâ, -tis, -tus, in which the t following the stressed syllable regularly became þ in Teutonic; in others, as growth, tillh, going back to ON. or OE.; in others, as blowth, spilth, stealth, of later analogical formation. In many words Indo-Eur. t remained in consequence of its position, or þ was subsequently changed to t: see -T suffix3 a.
b. from adjs. (rarely sbs.), representing Indo-Eur. -itâ, OTeut. -iþô, Goth. -iþa, OE. -þu, -þo, -þ, with prec. i- umlaut, forming abstract nouns of state: as filth (OE. fýlþ, OS. fūlitha from fúl foul), health, length, mirth, strength, truth; in ME. and also in cognate langs., dearth, depth; of later analogical formation, breadth, sloth (cf. OE. slǽwþ), wealth. In some words of this group, þ has, by phonetic causes, become t, e.g., OE. híehþu, ME. heiȝþe, now height, ON, slægð, ME. sleiȝþe, now sleight: see -T suffix3 b.
