What is the meaning of Forcer?

agent noun of force

The solid piston of a force pump; the instrument by which water is forced in a pump.

A small hand pump for sinking pits, draining cellars, etc.

A bell-shaped lidded pot for growing rhubarb, used to limit photosynthesis by excluding light, encouraging early-season growth and blanched stems.

to force

Source: wiktionary.org