English Reference

Word

lightweight

Phoneticslight·weight, stress on the first syllable

US/ˈɫaɪtˈweɪt/

UK/lˈaɪtweɪt/

Definitions

01combat sports

B2 · Upper Intermediate Countable noun Sports

n. a person who competes in a specific weight class, usually between featherweight and welterweight.

n. a professional weight division in sports such as boxing, wrestling, and MMA, typically falling between featherweight and welterweight.

“The lightweight won the championship after a very fast and exciting fight.”

“The lightweight division remains one of the most competitive in the sport, requiring a perfect balance of speed and punching power.”

Usage

Often used as a modifier before another noun, like 'lightweight champion'.

Synonyms

Antonyms

02unimportant person

C1 · Advanced Countable noun Informal

n. someone who is not important or does not have much influence or ability.

n. a person of little importance, influence, or intellectual depth.

“The other politicians ignored him because they thought he was a lightweight.”

“Despite his family connections, he was regarded as a political lightweight who lacked the gravitas to lead the party.”

Teaching tip

This is the metaphorical opposite of a 'heavyweight' in a professional or intellectual context.

Synonyms

nobodynonentity

Antonyms

03alcohol tolerance

B2 · Upper Intermediate Countable noun Informal

n. a person who gets drunk very quickly after only a small amount of alcohol.

n. an individual with a low physiological tolerance for alcohol.

“I am such a lightweight that I feel dizzy after just one glass of wine.”

“He earned a reputation as a lightweight among his colleagues after falling asleep at the first office happy hour.”

Teaching tip

This is a very common informal usage in social settings, often used in a lighthearted or self-deprecating way.

04not heavy

B2 · Upper Intermediate

adj. made of thin or light material; not weighing very much.

adj. having relatively little weight; specifically designed to be portable or easy to move.

“You should bring a lightweight jacket because it might get cool in the evening.”

“The hikers preferred lightweight carbon-fiber poles to reduce the strain on their joints during the long ascent.”

Synonyms

Antonyms

05computing

C1 · Advanced Computing Technical

adj. software that is small, fast, and does not use much of a computer's power.

adj. referring to software or protocols designed to have a small footprint and minimal impact on system resources.

“I use a lightweight browser because my old laptop cannot run the heavy ones.”

“The developers opted for a lightweight framework to ensure the application remained responsive even on older mobile hardware.”

Synonyms

Antonyms

06to make lighter

C2 · Proficiency Technical

v. to make something weigh less by using different materials.

v. to reduce the weight of a vehicle or structure, typically to improve performance or fuel efficiency.

“The engineers had to lightweight the car to meet the new racing rules.”

“By lightweighting the chassis with aluminum alloys, the manufacturer significantly improved the vehicle's power-to-weight ratio.”

Synonyms

Real-World Examples

“The tag is lightweight and designed to fall off naturally when the bird molts its feathers.”
Phys.org 22 Aug 2026
“She says shorts are "the trickiest item to get right in a professional environment" and recommends tailored, longer shorts paired with a crisp shirt or lightweight blazer for both men and women.”
BBC News 6 Aug 2026

Etymology

From light (“not heavy”, adjective) + weight (noun).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domains

ComputingSports

This entry

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.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL 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: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
Frequency
Frequent
Level
B2 · Upper Intermediate
Updated

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English Reference