corker

corker = cork (transparent) = cork + er

This is a regular instrumental/agentive noun built from the verb 'cork' plus '-er', so the meaning is straightforward.

Corker comes from the word cork, the stopper made from the bark of a tree, and the ending -er meaning 'one that does'. It was first used for a tool that puts a cork into a bottle, so a corker is a machine for inserting corks.