The indentation or depression made by the pressure of one object on or into another.

“His head made an impression on the pillow.”

The overall effect of something, e.g., on a person.

“He tried to make a good impression on his parents.”

A vague recalling of an event, a belief.

“I have the impression that he's already left for Paris.”

To manipulate a blank key within a lock so as to mark it with impressions of the shape of the lock, which facilitates creation of a duplicate key.