As nouns,
Hylobates syndactylus is a hyponym of
lesser ape; that is, Hylobates syndactylus is a
word with a more specific, narrower meaning than
lesser ape:
lesser ape: gibbons and siamangs
Hylobates syndactylus: large black gibbon of Sumatra having the 2nd and 3rd toes partially united by a web