Macaroni is a kind of pasta made in the shape of short hollow tubes. a type of pasta in the shape of small tubes macaroni cheese /macaroni and cheese (=macaroni cooked with a cheese sauce) (maccheroni, from maccarone, probably from makaria )
pasta in the form of slender tubes a British dandy in the 18th century who affected Continental mannerisms; "Yankee Doodle stuck a feather in his cap and called it macaroni
basically a fop: usually a member of a London club dressed in extreme fashion - bobtailed coat and high wig topped by a tricorn (referenced to in song Yankee Doodle)