concern vs bugaboo

concern and bugaboo both are nouns.

Word	Noun	Adjective	Verb	Adverb
concern	Yes	No	Yes	No
bugaboo	Yes	No	No	No

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

Other hyponyms of concern include burden, encumbrance, incumbrance, load, onus, business.

concern (noun)	bugaboo (noun)
something that interests you because it is important or affects you	a source of concern
something or someone that causes anxiety; a source of unhappiness	an imaginary monster used to frighten children
a feeling of sympathy for someone or something
an anxious feeling
a commercial or industrial enterprise and the people who constitute it

concern (verb)	bugaboo (verb)
be relevant to
be on the mind of