An electrical switch, in a generator or motor, that periodically reverses the direction of an electric current.
A binary map in a given group G, given by [g, h] = ghg⁻¹h⁻¹, where g and h are elements of G, which yields the group's identity if and only if the group operation commutes for g and h.
A binary map in a given ring R, given by [a, b] = ab − ba, where a and b are elements of R, which yields the ring's zero element if and only if the multiplication operation commutes for a and b.
A device (now often electrical) used to goad livestock into moving.
A production; a created work.
A light kind of crossbow; a prodd.
A prick or stab with such a pointed instrument.
A poke.
To encourage, to prompt.
To prick with a goad.
To poke, to push, to touch.