Answer:

carp

Answer	Crossword Clue
CARP	Grumble
CARP	Find fault in a disagreeable way
CARP	Freshwater catch

CARP	Pond fish
CARP	Bottom feeder
CARP	Food fish
CARP	Freshwater fish
CARP	Find fault
CARP	Complain
CARP	Beef
CARP	Complain gratingly

CARP	Complain habitually
CARP	Have lots of beefs
CARP	Koi
CARP	Koi and kin
CARP	Complaint
CARP	Beef and moan
CARP	Emulate a virago
CARP	Engage in nitpicking

CARP	Freshwater food fish
CARP	Be critical
CARP	Be overly picky
CARP	Fish that complains a lot?
CARP	Kvetch
CARP	Pick
CARP	Koi, for one
CARP	Nitpick

CARP	Complain constantly
CARP	Bellyache
CARP	Criticize
CARP	Moan and groan
CARP	Goldfish or koi
CARP	Beef, or a fish
CARP	Criticize trivially
CARP	Be picky

CARP	Niggle
CARP	Complain shrilly
CARP	Raise trivial objections
CARP	Gripe, gripe, gripe
CARP	Goldfish relative