from The American Heritage® Dictionary of the English Language, 4th Edition
- suffix Variant of -eth1.
- suffix Act; process: spilth.
- suffix State; quality: dearth.
- suffix Used to form ordinal numbers: millionth.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- suffix Forming nouns from verbs of action.
- suffix Forming nouns from adjectives.
- suffix Used to form the ordinal numeral when the final term of the spelled number is not "first", "second", or "third".
- suffix a variant of -eth, used to form the archaic third-person singular of verbs
Middle English, from Old English -thu, n. suff.
Middle English -the, from Old English -tha, -the.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Middle English -th, -t, from Old English -þ, -t, -þu, -tu, -þo, -to ("-th", abstract nominal suffix), from Proto-Germanic *-iþō (“-th”), from Proto-Indo-European *-itā (“-th”). Cognate with Scots -th ("-th"), West Frisian -te ("-th"), Dutch -te ("-th"), Danish -de ("-th"), Swedish -d ("-th"), Icelandic -ð, -d ("-th"), Gothic -𐌹𐌸𐌰 (-iþa, "-th"), Latin -itās ("-ty, -ity"). See -ity. (Wiktionary)
Representing Old English -þa, -þe, -oþa, -oþe, derived from a Proto-Indo-European superlative suffix. (Wiktionary)
Representing Old English -eþ, -aþ, -þ. (Wiktionary)