Word
unilateral
Phoneticsuni·lat·er·al
US/ˌjunəˈɫætɝəɫ/
UK/jˌuːnɪlˈætəɹəl/
Definitions
01one-sided decision
C1 · Advanced Formal · Academic
adj. describes a decision or action taken by one person or group without the agreement of others involved.
adj. performed by or affecting only one person, group, or country involved in a situation, without the agreement of another or others.
“The manager made a unilateral decision to change the office hours without asking the staff.”
“The country faced international criticism after its unilateral withdrawal from the climate treaty, which many saw as a betrayal of global cooperation.”
Usage
Commonly used in political, legal, and business contexts to describe actions taken without consultation.
Teaching tip
Learners should note the prefix 'uni-' (one) and compare it with 'bi-' (two) and 'multi-' (many) to understand the scope of the action.
Synonyms
Antonyms
02legal obligation
C2 · Proficiency Law Technical · Formal
adj. in law, an agreement where only one person or side has a duty to do something.
adj. denoting a contract or agreement in which only one party makes an express promise or undertakes a performance without receiving a reciprocal promise.
“A reward poster is a unilateral contract because only the person offering the money has a duty to pay.”
“The court ruled that the document constituted a unilateral obligation, as the defendant had promised payment without requiring any specific counter-performance.”
Usage
Used specifically in contract law to distinguish from bilateral agreements where both parties exchange promises.
Teaching tip
This is a highly specialized legal sense; for general purposes, the 'one-sided decision' sense is much more frequent.
Synonyms
Antonyms
03medical/physical
C1 · Advanced Medicine Technical
adj. affecting only one side of the body or one organ.
adj. occurring on, being confined to, or affecting only one side of the body or one of a pair of organs.
Español:unilateral
“The patient complained of unilateral hearing loss in her left ear.”
“The MRI scan confirmed a unilateral lesion on the right hemisphere of the brain, explaining the lack of motor control on the left side.”
Usage
Usually precedes the noun it modifies, such as 'unilateral pain' or 'unilateral weakness'.
Teaching tip
In medical English, this is the standard way to say 'on one side' rather than using everyday language.
Synonyms
Antonyms
Real-World Examples
“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.” Etymology
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.
Word family
ADJECTIVE
ADVERB
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
- Frequency
- Frequent
- Level
- C1 · Advanced
- Updated
- アルファベット
- 読み方の一覧 →
QR code
englishreference.com/q/unilateral
Traducciones: Kaikki.org (Wiktionary), CC BY-SA 4.0