presscap
nounUK /ˈprɛs.kæp/
US /ˈprɛs.kæp/
A presscap is a small cap you press down to close something tightly.
She pressed the presscap onto the bottle so the juice would not spill.
OTHER MEANINGS
2. A cap on a pen that you push on to keep the ink from drying out.
He clicked the presscap back onto his pen after writing.
3. A protective cover pressed onto a pipe or tube end.
The plumber fitted a presscap over the open pipe.
4. A small button-like cover pressed to seal a camera lens.
She put the presscap on the lens before packing the camera.