In the following question, select the odd word pair from the given alternatives.

Gun - Shoot

THE LOGIC;

The odd one is;

 Gun - Shoot

This is because the other word pairs represent an action and the tool or instrument used for that action (Write - Pen, Magnify - Microscope, Dig - Spade),

while in "Gun - Shoot," a gun is not a tool or instrument used for shooting; rather, a gun is the object that shoots.