What is the meaning of Washboard?

A board with a corrugated surface against which laundry may be rubbed.

Such a board used as a simple percussion instrument.

A board fastened along a ship's gunwale to prevent splashing; a splashboard.

A stretch of ripples or bumps on a dirt or gravel road caused by interaction between traffic and road surface.

baseboard; skirting board

To produce a rippled texture on a surface.

To play a washboard.

To move up and down or back and forth across the surface of a hive, possibly to lay down a layer of propolis and wax.

Source: wiktionary.org