unilateral
- 01 C1 Advanced
describes a decision or action taken by one person or group without the agreement of others involved.
performed by or affecting only one person, group, or country involved in a situation, without the agreement of another or others.
Simple“The manager made a unilateral decision to change the office hours without asking the staff.”
In context“The country faced international criticism after its unilateral withdrawal from the climate treaty, which many saw as a betrayal of global cooperation.”
UsageCommonly used in political, legal, and business contexts to describe actions taken without consultation.
Teacher's tipLearners should note the prefix 'uni-' (one) and compare it with 'bi-' (two) and 'multi-' (many) to understand the scope of the action.
SynonymsAntonyms - 02 C2 Proficiency
in law, an agreement where only one person or side has a duty to do something.
denoting a contract or agreement in which only one party makes an express promise or undertakes a performance without receiving a reciprocal promise.
Simple“A reward poster is a unilateral contract because only the person offering the money has a duty to pay.”
In context“The court ruled that the document constituted a unilateral obligation, as the defendant had promised payment without requiring any specific counter-performance.”
UsageUsed specifically in contract law to distinguish from bilateral agreements where both parties exchange promises.
Teacher's tipThis is a highly specialized legal sense; for general purposes, the 'one-sided decision' sense is much more frequent.
SynonymsAntonyms - 03 C1 Advanced
affecting only one side of the body or one organ.
occurring on, being confined to, or affecting only one side of the body or one of a pair of organs.
Simple“The patient complained of unilateral hearing loss in her left ear.”
In context“The MRI scan confirmed a unilateral lesion on the right hemisphere of the brain, explaining the lack of motor control on the left side.”
UsageUsually precedes the noun it modifies, such as 'unilateral pain' or 'unilateral weakness'.
Teacher's tipIn medical English, this is the standard way to say 'on one side' rather than using everyday language.
Synonymsone sidedAntonyms
“It said that it was firmly opposed to what it called "illegal unilateral sanctions", that economic pressure tactics would not help resolve problems and that Beijing would safeguard its own interests.”
“Foreign ministry spokesman Lin Jian said China was firmly opposed to what it called "illegal unilateral sanctions" and would take "all necessary measures" to safeguard its rights.”
A modern creation (circa 1802), from New Latin ūnilaterālis (“one-sided”), from Latin ūnus (“one”) + laterālis (“sided, lateral”), equivalent to uni- + lateral.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.