a type of military landing ship slightly more than 200 feet (60 meters) long.
Origin of LSM
l(anding) s(hip) m(edium)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for lsm
Lauer pointed out that for the morning, at least, she was a member of the “LSM” herself.Sarah Palin Hosts ‘Today’ and Auditions for a Broader Role|Nick Summers|April 3, 2012|DAILY BEAST