underarm

Still, airy stretch-woven nylon panels across the back and underarms dissipate sweat and permit a full range of motion, so testers stayed comfortable in zero-degree temperatures, even when they were huffing and puffing up the skin track.
The Best Jackets of 2022|jversteegh|October 26, 2021|Outside Online
Even on the first wear, there was no underarm or neckline chafing.
There’s Never Been a Better Time to Buy a Sustainable Wetsuit|wtaylor|July 23, 2021|Outside Online
It features mesh underarm vents, five percent spandex for stretch, and UPF 50 fabric that keeps me cool and comfortable no matter how hot it gets.
The Gear Our Editors Loved in June|The Editors|July 2, 2021|Outside Online
The underarm panels didn’t seem to compromise warmth but were a welcome feature while moving above the tree line during fall hikes up Bear Peak in Boulder, Colorado, with early-morning temperatures in the high forties.
Do You Actually Need a 1,000-Fill Down Jacket?|Ryan Wichelns|December 23, 2020|Outside Online

In fitting the outside the back is pinned on to the lining firmly, then the front and finally at the underarm seams.
Textiles and Clothing|Kate Heintz Watson
An underarm dart gives a smooth adjustment over each hip, and in these darts are inserted the back edges of the vest.
Prairie Farmer, Vol. 56: No. 1, January 5, 1884.|Various
Baste seams of sleeve and underarm all in one long seam on right side.
Clothing and Health|Helen Kinne
Mark with tracing or pencil the new seam for underarm if you must change it.
Clothing and Health|Helen Kinne
Baste, with the seams on the outside, shoulder, and underarm seams.
Clothing and Health|Helen Kinne

British Dictionary definitions for underarm

underarm

/ (ˈʌndərˌɑːm) /

adjective

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

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

below the arm

adverb

in an underarm style

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for underarm

underarm

[ ŭn′dər-ärm′ ]

adj.

Located, placed, or used under the arm.

The armpit.