An old fashioned way to describe a gay person.
Mavis and Madge were sitting in the marketplace waiting for the post office to open so they could collect their pensions. As usual, they were gossiping...
<Mavis> Did you know Mr Johnson from the butchers got caught smooching Mr Winslow from the grocers?
<Madge - checks over both shoulders nervously and whispers> WHAT?! I can't believe it! Although, come to think of it, he always has "walked with a light step".
<Mavis> Meh, I always knew he was a shirtlifter