Answer:

griper

Answer	Crossword Clue
GRIPER	Beef producer?
GRIPER	Malcontent
GRIPER	Complaining sort

GRIPER	Grouser: Slang.
GRIPER	G. I. grumbler.
GRIPER	Complainer
GRIPER	Bellyaching sort

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.