lightweight

American  

[lahyt-weyt] / ˈlaɪtˌweɪt /

adjective

1. light in weight.

2. being lighter in weight, texture, etc., than another item or object of identical use, quality, or function: a lightweight alloy for ship construction.

   a lightweight topcoat;

   a lightweight alloy for ship construction.

3. without seriousness of purpose; trivial or trifling.

   lightweight reading.

4. of or relating to a lightweight.

   He's the new lightweight contender.

5. (of a horse, especially a hunter) able to carry up to 165 pounds (75 kilograms).

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noun

lightweights plural

1. a person of less than average weight.

2. Informal. a person who is of little influence, importance, or effect.

3. a boxer or other contestant intermediate in weight between a featherweight, and a welterweight, especially a professional boxer weighing between 126 and 135 pounds (56.7–61 kilograms).

lightweight British  

/ ˈlaɪtˌweɪt /

adjective

1. of a relatively light weight

2. not serious; trivial

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noun

1. a person or animal of a relatively light weight

2. 1. a professional boxer weighing 130–135 pounds (59–61 kg)

   2. an amateur boxer weighing 57–60 kg (126–132 pounds)

   3. ( as modifier )

      the lightweight contender

3. a wrestler in a similar weight category (usually 115–126 pounds (52–57 kg))

4. informal a person of little importance or influence

Other Word Forms

Derived Forms

• ultralightweight
  adjective

Inflected Forms

Nouns

• lightweights
  plural

Etymology

Origin of lightweight

First recorded in 1765–75; light ² + weight

Explanation

When an object is lightweight, it weighs much less than other similar objects. A person is a lightweight if they can't handle much — if you get full after a small meal, big eaters might refer to you as a lightweight. Break lightweight apart — light + weight — and you see its definition right there in its root words. Someone who is called a lightweight is either a professional boxer who weighs under 135 pounds or he's someone with little importance or ability. When a company is looking to make layoffs, it's the lightweight employees, or those who just aren't important to the business that often get axed first.

Example Sentences

“Ragin’ ” Al, a low-ranked fighter known for decent grappling and heavy hitting, had no business fighting for the lightweight strap.

From Slate • Jun. 14, 2026

Undisputed lightweight champion Ilia Topuria will face off against current interim lightweight champion Justin Gaethje in the main event, which is billed as a five-round title unification battle.

From Los Angeles Times • Jun. 11, 2026

The show is headlined by a unification bout between Georgian-Spanish lightweight champion Ilia Topuria and American interim title holder Justin Gaethje.

From BBC • Jun. 4, 2026

Britain’s Lotus LOT 0.00%increase; green up pointing triangle is known for its lightweight sports cars, its appearances in James Bond films, and its many brushes with financial collapse.

From The Wall Street Journal • May 31, 2026

No sufficiently powerful and lightweight engine then existed.

From "Cosmos" by Carl Sagan