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.
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.
F partitif -ive or med.L partitivus (as PARTITE)