Definition of "bathers"

The bathers they wore looked sort of the same as now, but their hair was really different.

2001, Laurene Kelly, The Crowded Beach‎, page 10

No one here wore bathers. Both boys wore their homemade underpants, the brand name, ‘Sydney Flour’, emblazoned across the back, as old flour bags were not wasted, but recycled.

2008, Lyn Aldred, Neptune's Fingers‎, page 10

I was looking at a pair of bathers to buy and talking about the life of the bathers and how to extend their life.

2009, Jacqueline Ann Wharton, Freedom Through Adversity: Ten Steps to Overcoming a Troubled Mind‎, page 69