IPA: /ɪnˈfɔːrməlɪti/
KK: /ɪnˈfɔrməlɪti/
The quality or state of being casual and relaxed, rather than formal or strict.
The informality of the gathering made everyone feel comfortable and at ease.
Informality → It is formed from "in-" (meaning not) and "formal" (from Latin "formalis", meaning pertaining to form or structure) and the suffix "-ity" (meaning the state or quality of). The word "informality" refers to the state of being not formal or lacking strict structure.
Think of 'not' ('in-') being combined with 'formal' to remember that 'informality' means a lack of strict formality.