Synonyms for fin

the cardinal number that is the sum of four and one (noun)

• five
• 5
• v
• cinque
• quint
• quintet
• fivesome
• quintuplet
• pentad
• phoebe

one of a pair of decorations projecting above the rear fenders of an automobile (noun)

• tailfin

one of a set of parallel slats in a door or window to admit air and reject rain (noun)

• louver
• louvre

a shoe for swimming (noun)

• flipper

show the fins above the water while swimming (verb)