1. without formality or ceremony; casual: an informal visit. 2. not according to the prescribed, official, or customary way or manner; irregular; unofficial: informal proceedings. 3. suitable to or characteristic of casual or familiar speech or writing.
Definition of informal adjective from the Oxford Advanced Learner's Dictionary. relaxed and friendly; not following strict rules of how to behave or do something. Discussions are held on an informal basis within the department. The aim of the trip was to make informal contact with potential customers.
Informal speech or behaviour is relaxed and friendly rather than serious, very correct, or official. She is refreshingly informal. His friend was less good-looking, but a lot more informal and relaxed.
not formal or ceremonious; casual. The informal manner in which she spoke to the boss annoyed some of her co-workers. Try not to be too informal with the job interviewer because it might not make a good impression. It was such an informal wedding that most people were wearing jeans and T-shirts.
If something’s informal, it’s casual and relaxed and doesn’t follow any particular rules or conventions, whether that's a style of writing, or the dress code for your dinner party.
Informal Terms, Linguistics suitable to or characteristic of casual and familiar, but educated, speech or writing. Grammar characterizing the second singular pronominal or verbal form, or its use, in certain languages: the informaltu in French.
