What is the meaning of Gaffer?

A chief lighting technician for a motion-picture or television production.

A glassblower.

Someone aboard a boat whose duty is to gaff a (large) fish once the angler has reeled it in.

An old man.

The leader of a group or team, such as a boss, foreman, coach, or publican.

A sailor.

The baby in the house.

to make a gaffe; to mess up; botch up

to gaffer tape

gaffer tape

to grasp

Soft mutation of caffer.

Source: wiktionary.org