boo vs hiss

boo and hiss both are nouns.

Word	Noun	Adjective	Verb	Adverb
boo	Yes	No	Yes	No
hiss	Yes	No	Yes	No

As nouns, boo and hiss are synonyms defined as:

Other synonyms of boo include bird, Bronx cheer, hoot, raspberry, razz, razzing, snort.

As verbs, boo and hiss are synonyms defined as:

boo (noun)	hiss (noun)
a cry or noise made to express displeasure or contempt	a cry or noise made to express displeasure or contempt
	a fricative sound (especially as an expression of disapproval)

boo (verb)	hiss (verb)
show displeasure, as after a performance or speech	make a sharp hissing sound, as if to show disapproval
	express or utter with a hiss
	show displeasure, as after a performance or speech
	move with a whooshing sound