Having only one arm; especially having lost an arm.

Having only one leg. / Of an audio signal: having a thin sound as a result of connection through only one wire of a circuit pair.

A plant, especially a tree.

(biblical) The Devil; Satan; Lucifer.

Allowing movement in only one direction; unidirectional. / Allowing travel in only one direction.

(agriculture) To use a disc harrow to turn the soil and kill weeds, in preparation for planting seeds.

(idiomatic) Close to death.

Partial or biased in favour of one faction or demographic group. / With one competitor dominant over the other. / Out of proportion or lopsided. / Having only one side, like a Möbius strip.

(reciprocal pronoun) Used of a reciprocal relationship among a group of two or more people or things; compare each other.

(set phrase) At some unspecified time in the future. / At some unspecified time in the past. / Used other than figuratively or idiomatically: see one, day.