brushwood vs thicket

brushwood and thicket both are nouns.

Word	Noun	Adjective	Verb	Adverb
brushwood	Yes	No	No	No
thicket	Yes	No	No	No

As nouns, brushwood and thicket are synonyms defined as:

Other synonyms of brushwood include brush, coppice, copse.

brushwood (noun)	thicket (noun)
a dense growth of bushes	a dense growth of bushes
the wood from bushes or small branches