dicky vs dicky-seat

dicky and dicky-seat both are nouns.

Word	Noun	Adjective	Verb	Adverb
dicky	Yes	Yes	No	No
dicky-seat	Yes	No	No	No

As nouns, dicky and dicky-seat are synonyms defined as:

dicky and dicky-seat: a small third seat in the back of an old-fashioned two-seater

Other synonyms of dicky include dickey-seat, dickey, dickie-seat, dickie.

dicky (noun)	dicky-seat (noun)
a man's detachable insert (usually starched) to simulate the front of a shirt	a small third seat in the back of an old-fashioned two-seater
a small third seat in the back of an old-fashioned two-seater

dicky (adjective)	dicky-seat (adjective)
(British informal) faulty