impression

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

   His head made an impression on the pillow.

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

   He tried to make a good impression on his parents.

3. A vague recalling of an event, a belief.

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

4. An impersonation, an imitation of the mannerisms of another individual.
5. An outward appearance.
6. An online advertising performance metric representing an instance where an ad is shown once.
7. The first coat of colour, such as the priming in house-painting etc.
8. (engraving) A print on paper from a wood block, metal plate, etc.
9. The vivid perception of something as it is experienced, in contrast to ideas or thoughts drawn from memory or the imagination.

verb

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.