'Grumbler' definitions:

Definition of 'grumbler'

From: WordNet
noun
A person given to excessive complaints and crying and whining [syn: whiner, complainer, moaner, sniveller, crybaby, bellyacher, grumbler, squawker]

Definition of 'Grumbler'

From: GCIDE
  • Grumbler \Grum"bler\, n. One who grumbles. [1913 Webster]