Giggles looking at unusual gorillas' hairy, snarling faces (6)
I believe the answer is:
laughs
'giggles' is the definition.
(giggling is a type of laughter)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for laughs that I've seen before include "Shows amusement" , "Expresses mirth" , "Splits one's sides" , "Jokes" , "He who ... last, ... longest, they say" .)