A lens cap is the cover that protects the glass at the front of a camera. Take off the lens cap.
It is the single most lost item in photography, which is why some are on strings. A lens cap left on is the first thing anybody checks when a picture comes out black.
1nounlens capThe cover that protects the glass at the front of a camera.
“The lens cap was in a field somewhere in the Peak District.”
lens cap is a cover.
Lens plus cap, from Latin lens, a lentil, named for the shape of the glass.
From lens + cap.
Etymology from Wiktionary, CC BY-SA
Practised in Photography & Film