lightweight

Noun

lightweight (plural lightweights)

1. (combat sports) A particular weight class, or member of such, as prescribed by the rules, between that of the heavier welterweight and the lighter featherweight. See Wikipedia for the specifics of each sport.
2. A particular weight category as prescribed by the rules, separate from an open or heavyweight class.
3. A competitive weight division as prescribed by the rules, between the heavier middleweight and the lighter featherweight.
4. One of little consequence or ability.
5. A person who cannot handle their drink; one who gets drunk on very little alcohol.
   • "Wait, is this about the other night when you two lightweights totally went on that bender?"2005 August 23, Haley Hazelton, Misfile (webcomic), 2005-08-23
6. (broadly) A person with low endurance.
7. A political candidate with little chance of winning.
8. Something that is light in weight, or relatively so.
   • He mentions the "huge engine, lying on its side"—it was in fact a 2-2-2 weighing but 27 tons, something of a lightweight, even for 1868.1958 May, Rev. A. W. V. Mace, “North Wales and the "Irish Mail"”, in Railway Magazine, page 309

Adjective

US/laɪtˈweɪt/

lightweight (comparative more lightweight or lighterweight, superlative most lightweight or lightestweight)

1. Lacking in earnestness, ability, or profundity.
2. Having less than average weight.
   • […] the Plan incorporates in proper combination every available modern technique, including extensive electrification on the new standard high-voltage a.c. system at a frequency of 50 cycles; main-line diesel traction as a half-way house to electrification; lightweight diesel trains for secondary...1958 January, 'Borderer', “Ten Years of British Railways”, in Railway Magazine, page 15
   • For example, lightweight construction and Jacobs bogies save weight, and a lighter train uses less power.2021 May 19, David Clough, “Swiss precision meets UK growth”, in RAIL, number 931, page 57
3. Lacking in strength.
   • With the Gunners far too lightweight in midfield, Mikel Arteta dropped back into a deeper-lying role. This freed Yossi Benayoun to go further forward, a move that helped forge a rare Arsenal chance on 30 minutes when the Israeli released Van Persie, only for the Dutchman's snap-shot to be tipped...2011 September 13, Sam Lyon, “Borussia Dortmund 1 - 1 Arsenal”, in BBC
4. Having a small footprint or performance impact.

Verb

lightweight (third-person singular simple present lightweights, present participle lightweighting, simple past and past participle lightweighted)

1. (transitive) To reduce the amount or weight of.
   • By extending the producer’s responsibility to the product’s disposal (its post-consumer life), issues previously outside the business calculus become of paramount importance. Because a producer knows it will have to bear the cost of collecting and valorizing the product, it must manage a new set of...1997 December 22, James Salzman, “Sustainable consumption and the law”, in Environmental Law
   • The solar photovoltaic array, GPS antennae and telephony antenna all would be lightweighted and integrated into the balloon structure, and the sensor-module would be ruggedized and miniaturized.2002, Edward Teller, Cecil Leith, Gregory Canavan, Lowell Wood, “Long-Range Weather Prediction III: Miniaturized Distributed Sensors for Global Atmospheric Measurements”, in A. Zichichi, R. Ragaini...