group vs collocate

group is a noun but collocate is not a noun.

Word	Noun	Adjective	Verb	Adverb
group	Yes	No	Yes	No
collocate	No	No	Yes	No

As verbs, collocate is a hyponym of group; that is, collocate is a word with a more specific, narrower meaning than group:

Other hyponyms of group include regroup, bracket, chunk, lump, batch.

group (noun)	collocate (noun)
any number of entities (members) considered as a unit
a set that is closed, associative, has an identity element and every element has an inverse
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule

group (verb)	collocate (verb)
arrange into a group or groups	group or chunk together in a certain order or place side by side
form a group or group together	have a strong tendency to occur side by side