partitive
adjective
par·ti·tive ˈpär-tə-tiv 
1
: serving to part or divide into parts
2
a
: of, relating to, or denoting a part
a partitive construction
b
: serving to indicate the whole of which a part is specified
partitive genitive
partitively adverb
Word History
First Known Use
14th century, in the meaning defined at sense 1