Shirtless adjective
(Of a man) Not wearing any clothes from the waist up.
Whenever I work out, I go shirtless.
All the girls in my class went crazy when seeing a muscular, shirtless man running past.
They found him shirtless and bleeding to death.
Naked
Completely naked
1. Used to talk about a wide happy smile
2. Used to describe someone naked
The origin of this adjective is not clear.
It was often said by a photographer when he would like small children to look at the camera and smile before he took a photo.
When the photographer said “watch the birdie”, all of us looked at the camera and smiled.