underarm

American  

[uhn-der-ahrm] / ˈʌn dərˌɑrm /

adjective

1. of, situated, or for use under the arm or in the armpit.

   an underarm deodorant.

2. underhand.

   an underarm pitch in softball.

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noun

1. armpit.

adverb

1. underhand.

underarm British  

/ ˈʌndərˌɑːm /

adjective

1. (of a measurement) extending along the arm from wrist to armpit

2. sport of or denoting a style of throwing, bowling, or serving in which the hand is swung below shoulder level

3. below the arm

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adverb

1. in an underarm style

Etymology

Origin of underarm

First recorded in 1810–20; under- + arm ¹

Example Sentences

But Moutet reeled off four straight games from 0-3 down, throwing in some underarm serves, dropshots and tweeners for good measure.

From Barron's • Jan. 23, 2026

Moutet has used the underarm tactic before, sending down six of them during his second-round win against Daniel Altmaier in Mallorca last year.

From Barron's • Jan. 18, 2026

Frenchman Corentin Moutet defended his tactics Sunday after serving underarm on match-point against home hope Tristan Schoolkate at the Australian Open.

From Barron's • Jan. 18, 2026

One advert for a deodorant called Mum, published in an American magazine in 1938, urged women to "face the truth about underarm perspiration odour".

From BBC • Oct. 16, 2025

Maybe it’s a puberty thing, like acne and underarm hair.

From "The Manifestor Prophecy" by Angie Thomas