Noun
(roofing) A half-cylindrical or half-conical shaped opening or void in a lapped edge or seam, usually caused by wrinkling or shifting of ply sheets during installation.
(surgery) A wide incision made to drain fluid from under the fingernail.
(surgery) A horizontal incision on the breast aligned with the nipples made to drain or excise the breast fat as a form of top surgery.
(colloquial) A chronically open mouth.
Source: en.wiktionary.org