- pertaining to a contract that can be formed only when the party to whom an offer is made renders the performance for which the offeror bargains.
- pertaining to a contract in which obligation rests on only one party, as a binding promise to make a gift.
Origin of unilateral
1802, from Modern Latin unilateralis, from unum, neuter of unus "one" (see one) + latus (genitive lateralis) "side" (see oblate (n.)). Jeremy Bentham (1748-1832) may have been the first to use it in the legal sense of "made or entered into by one party." Unilateral disarmament is recorded from 1929.
It is useless for the sheep to pass resolutions in favor of vegetarianism, while the wolf remains of a different opinion. [William Ralph Inge, "Outspoken Essays," 1919]