Толковый словарь английского языка Oxford English Reference - partitive

adj. & n. Gram. --adj. (of a word, form, etc.) denoting part of a collective group or quantity. --n. a partitive word (e.g. some, any) or form. Phrases and idioms partitive genitive a genitive used to indicate a whole divided into or regarded in parts, expressed in English by of as in most of us. Derivatives partitively adv. Etymology: F partitif -ive or med.L partitivus (as PARTITE)