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 conductor maintained at a fixed electrical potential relative to ground, to which other circuit components are connected.
A horizontal bar extending between supports and used for support or as a barrier; a railing.
A large line (portion or serving of a powdery illegal drug).
A railroad; a railway, as a means of transportation.
Any of several birds in the family Rallidae.
One of the lengthwise edges of a surfboard.
A horizontal piece of wood that serves to separate sections of a door or window.
The metal bar forming part of the track for a railroad.
A vertical section on one side of a web page.
To enclose with rails or a railing.
To range in a line.
To place on a track.
To sexually penetrate in a rough manner.
To travel by railway.
To complain violently (against, about).