pygmy chimpanzee vs chimp

pygmy chimpanzee and chimp both are nouns.

Word	Noun	Adjective	Verb	Adverb
pygmy chimpanzee	Yes	No	No	No
chimp	Yes	No	No	No

As nouns, chimp is a hypernym of pygmy chimpanzee; that is, chimp is a word with a broader meaning than pygmy chimpanzee:

pygmy chimpanzee: small chimpanzee of swamp forests in Zaire; a threatened species
chimp: intelligent somewhat arboreal ape of equatorial African forests

Other hypernyms of pygmy chimpanzee include chimpanzee, Pan troglodytes.

pygmy chimpanzee (noun)	chimp (noun)
small chimpanzee of swamp forests in Zaire; a threatened species	intelligent somewhat arboreal ape of equatorial African forests