a close-fitting, low-cut top having shoulder straps and often made of lightweight, knitted fabric.
Origin of tank top
First recorded in 1945–50
Also called tank.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a sleeveless upper garment with wide shoulder straps and a low neck, usually worn over a shirt, blouse, or jumper
Word Origin for tank top
C20: named after tank suits, one-piece bathing costumes of the 1920s worn in tanks or swimming pools
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
1968, from tank suit "one-piece bathing costume" (1920s), so called because it was worn in a swimming tank (n.), i.e. pool.
Online Etymology Dictionary, © 2010 Douglas Harper