dicky vs dickey-seat

dicky and dickey-seat both are nouns.

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

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

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

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

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