Fit in Definition 1 of 3Pro Tip 1/3Social Acceptance Refers to being accepted by others, making friends, or feeling like you belong. She really fits in with her classmates. Pro Tip 2/3Conformity Pressure Used when someone feels the need to change to be accepted by others. He tried hard to fit in by copying their style. Pro Tip 3/3Colloquial Context Often used in casual conversation rather than formal writing. At the new school, will I fit in?