What is the meaning of Martinet?

A strict disciplinarian.

Anyone who lays stress on a rigid adherence to the details of discipline, or to forms and fixed methods or rules.

A short whip with multiple lashes once used in France.

A martin; a swift.

heron (a wading bird of the family Ardeidae)

multi-tail whip, comprising leather or whipcord thongs fixed on a handle, to dust off or to administer a beating

mechanical hammer on a motor-driven cogwheel, as used to beat metal

martin (any of the swallow-like birds, black with a white throat, of family Hirundinidae)

swift (bird)

Source: wiktionary.org