source: Cherry Blossom Destiny - GIF on Imgur

1. an idea, feeling, or opinion about something or someone, especially one formed without conscious thought or on the basis of little evidence:

〖通例修飾語を伴って〗 «…についての/…という/人へ与える» 印象, 感銘, 感動 «of/that節/on»;〖通例単数形で〗 «…という» (漠然とした)感じ, 気持ち «that節, of»

e.g. his first impressions of Manchester were very positive

e.g. they give the impression that all is sweetness and light.

an effect produced on someone:

«…への» 効果, 影響 «on, upon»

e.g. her courtesy and quick wit had made a good impression.

a difference made by the action or presence of someone or something:

e.g. the floor was too dirty for the mop to make much impression.

2. an imitation of a person or thing, especially one done to entertain:

(有名人の)物まね(impersonation)

e.g. he did an impression of Frank Sinatra.

a graphic or pictorial representation of someone or something:

e.g. the police have issued an artist's impression of the attacker.

3. a mark impressed on a surface by something:

(押しつけてできた) «…への» 印, 跡 «on, in»

e.g. 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.

〘印〙 刷り(→ edition); (一度に刷った)総部数

usually with modifier chiefly British a particular printed version of a book or other publication, especially 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 online advertisement being seen on an Internet user's monitor.

believing, mistakenly or on the basis of little evidence, that something is the case:

e.g. he was under the impression that they had become friends.

impressional |-SHənl| adjective

late Middle English: via Old French from Latin impressio(n-), from impress- ‘pressed in’, from the verb imprimere (see imprint).