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.

---

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

---

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

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

The ball jingles and is bowled underarm along the pitch.

From BBC • Nov. 21, 2025

The tension has led to arguments over on-court etiquette - or the lack of it - with net cords, underarm serves and body shots all under scrutiny.

From BBC • Sep. 3, 2025

There was something about her face in that moment that was weird, like something invisible was pinching her underarm.

From "Patina" by Jason Reynolds