The noun impression has 9 senses (first 3 from tagged texts)
1. (14) impression, feeling, belief, notion, opinion -- (a vague idea in which some confidence is placed; "his impression of her was favorable"; "what are your feelings about the crisis?"; "it strengthened my belief in his sincerity"; "I had a feeling that she was lying")
2. (6) impression, effect -- (an outward appearance; "he made a good impression"; "I wanted to create an impression of success"; "she retained that bold effect in her reproductions of the original painting")
3. (1) mental picture, picture, impression -- (a clear and telling mental image; "he described his mental picture of his assailant"; "he had no clear picture of himself or his world"; "the events left a permanent impression in his mind")
4. depression, impression, imprint -- (a concavity in a surface produced by pressing; "he left the impression of his fingers in the soft mud")
5. stamp, impression -- (a symbol that is the result of printing; "he put his stamp on the envelope")
6. impression, printing -- (all the copies of a work printed at one time; "they ran off an initial printing of 2000 copies")
7. impression -- ((dentistry) an imprint of the teeth and gums in wax or plaster; "the dentist took an impression for use in preparing an inlay")
8. impression -- (an impressionistic portrayal of a person; "he did a funny impression of a politician")
9. impression -- (the act of pressing one thing on or into the surface of another; "he watched the impression of the seal on the hot wax")