Main gauche

Main gauche means 'left hand' and refers to a slender dagger used in that same hand when engaged with a combat with anther weapon, typically a rapier.

They often had curved quillions and a small basket hilt to protect the hand and were used point up with the thumb resting on the flat of the blade.

The Scot's Left Handed Dagger is a variation on the main gauche and features a much larger blade than would typically be seen. This was often used in conjuction with a basket hilted sword and dates from the late 16th to 17th century.