Grouser

noun

1. A temporary pile or heavy iron-shod pole driven into the bottom of a stream to hold a drilling-or dredging-boat or other floating object in position.
2. A pointed timber attached to a boat and sliding vertically, to thrust into the ground as a means of anchorage.
3. A person who grouses; a grumbler
4. A temporary pile driven into the bottom of a river to hold a boat in position; a spud
5. A protrusion on the surface of a wheel or continuous track segment, intended to increase traction in soil, snow, or other loose material