gimcrack vs tacky

gimcrack is a noun but tacky is not a noun.

Word	Noun	Adjective	Verb	Adverb
gimcrack	Yes	Yes	No	No
tacky	No	Yes	No	No

As adjectives, gimcrack and tacky are synonyms defined as:

Other synonyms of gimcrack include brassy, cheap, flash, flashy, garish, gaudy, loud, meretricious, tatty, tawdry, trashy.

gimcrack (noun)	tacky (noun)
ornamental objects of no great value

gimcrack (adjective)	tacky (adjective)
tastelessly showy	tastelessly showy
	(of a glutinous liquid such as paint) not completely dried and slightly sticky to the touch