bird vs boo

bird and boo both are nouns.

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

As nouns, bird and boo are synonyms defined as:

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

bird (noun)	boo (noun)
warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings	a cry or noise made to express displeasure or contempt
badminton equipment consisting of a ball of cork or rubber with a crown of feathers
a cry or noise made to express displeasure or contempt
the flesh of a bird or fowl (wild or domestic) used as food
informal terms for a (young) woman

bird (verb)	boo (verb)
watch and study birds in their natural habitat	show displeasure, as after a performance or speech