One who complains

• Constant complainer
• Constant grumbler

Wikipedia Word definitions in Wikipedia
Grousers are devices intended to increase the traction of continuous tracks , especially in loose material such as soil or snow . This is done by increasing contact with the ground with protrusions, similar to conventional tire treads, and analogous to ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Grouser \Grou"ser\, n. ( Dredging , Pile Driving , etc.) A pointed timber attached to a boat and sliding vertically, to thrust into the ground as a means of anchorage.

Wiktionary Word definitions in Wiktionary
n. 1 A person who grouses; a grumbler 2 (context nautical English) A temporary pile driven into the bottom of a river to hold a boat in position; a spud 3 (context engineering English) A protrusion on the surface of a wheel or continuous track segment, ...