boob vs sideboob

boob and sideboob both are nouns.

Word	Noun	Adjective	Verb	Adverb
boob	Yes	No	Yes	No
sideboob	Yes	No	No	No

As nouns, sideboob is a hyponym of boob; that is, sideboob is a word with a more specific, narrower meaning than boob:

boob: either of two soft fleshy milk-secreting glandular organs on the chest of a woman
sideboob: A breast exposed from the side

boob (noun)	sideboob (noun)
either of two soft fleshy milk-secreting glandular organs on the chest of a woman	A breast exposed from the side
an ignorant or foolish person

boob (verb)	sideboob (verb)
commit a faux pas or a fault or make a serious mistake