I. un ‧ der ‧ arm 1 /ˈʌndərɑːm $ -ɑːrm/ BrE AmE adverb
British English if you throw a ball underarm, you throw it without moving your arm above your shoulder OPP overarm SYN underhand American English
II. underarm 2 BrE AmE adjective
1 . [only before noun] relating to or used on your ↑ armpit s :
underarm hair
underarm deodorants
2 . an underarm throw is one where you throw a ball without moving your arm above your shoulder OPP overarm :
underarm bowling
III. underarm 3 BrE AmE noun [countable]
the hollow area under your arm, where it joins your body SYN armpit