- word-forming element used in making adjectives, from Old English -sum (see some; and cf. Old Frisian -sum, German -sam, Old Norse -samr), related to sama "same."
As a suffix added to numerals meaning "a group of that number" (cf. twosome) it represents Old English sum "some," used after the genitive plural (cf. sixa sum "six-some"), the inflection disappearing in Middle English. Use of some with a number meaning "approximately" also was in Old English.