- Whilst is defined as while and refers to things going on at the same time as something else.
If you fall asleep as you are watching a movie, this is an example of a situation where you fall asleep whilst watching a movie.
whilst definition by Webster's New World
Origin: Middle English whilest, extended ; from whiles, whiles
whilst definition by American Heritage Dictionary
conjunction Chiefly British
Origin: Middle English whilest, alteration of whiles, whiles; see whiles.