mouse

• mouse [countable]
• 1 plural mice a small furry animal with a pointed nose and a long tail that lives in people's houses or in fields:
• The cat laid a dead mouse at my feet.
• a field mouse
• 2 plural mouses a small object connected to a computer by a wire, which you move with your hand to give instructions to the computer:
• Select the printer icon and then click the left mouse button.
• 3 plural mice informal a quiet, nervous person

• ➔ play cat and mouse

  at cat (4)

  ; ➔ quiet as a mouse

  at quiet1 (1)

Definition from the Longman Dictionary of Contemporary English
Advanced Learner's Dictionary.