informal
B2Adjektiv/US /ˌɪnfˈɔrməl/ ĭnf-ÔRM-əl; UK /ˌɪnfˈɔrməl/ ĭnf-ÔRM-əl/
Not in the regular, usual, or established form; not according to official, conventional, prescribed, or customary forms or rules; irregular; hence, without ceremony; as, an informal writting, proceeding, or visit.
