impression

im·pres·sion / imˈpreshən/ • n. 1. an idea, feeling, or opinion about something or someone, esp. one formed without conscious thought or on the basis of little evidence: his first impressions of Manchester were very positive they give the impression that all is sweetness and light. ∎  an effect produced on someone: her courtesy and quick wit had made a good impression. ∎  a difference made by the action or presence of someone or something: the floor was too dirty for the mop to make much impression. 2. an imitation of a person or thing, esp. one done to entertain: he did an impression of Frank Sinatra. ∎  a graphic or pictorial representation of someone or something: the police have issued an artist's impression of the attacker. 3. a mark impressed on a surface by something: the impression of his body on the leaves. ∎  Dentistry a negative copy of the teeth or mouth made by pressing them into a soft substance. 4. the printing of a number of copies of a book, periodical, or picture for issue at one time. ∎  a particular printed version of a book or other publication, esp. one reprinted from existing type, plates, or film with no or only minor alteration.Compare with edition. ∎  a print taken from an engraving. 5. an instance of a pop-up or other Web advertisement being seen on computer users' monitors: Nielsen/NetRatings reported Web publishers served 7.3 billion pop-up ad impressions. PHRASES: under the impression that believing, mistakenly or on the basis of little evidence, that something is the case: he was under the impression that they had become friends.DERIVATIVES: im·pres·sion·al / -shənl/ adj.