a native English suffix denoting state, condition, character, nature, etc., or a body of persons of a particular character or class, formerly used in the formation of nouns: childhood; likelihood; knighthood; priesthood.
Origin of -hood
Middle English-hode, -hod,Old English-hād (cognate with German-heit), special use of hād condition, state, order, quality, rank
word-forming element meaning "state or condition of being," from Old English -had "condition, position," cognate with German -heit, Dutch -heid, all from Proto-Germanic *haidus "manner, quality," literally "bright appearance," from PIE (s)kai- (1) "bright, shining." Originally a free-standing word (see hade); in Modern English it survives only in this suffix.