WordNet sense 1 (not officially recognized or controlled):

loose

WordNet sense 2 (not having official authority or sanction):

unofficial

WordNet sense 3 (having or fostering a warm or friendly and informal atmosphere):

cozy, intimate, intimate

WordNet sense 4 (characteristic of or befitting a friend):

friendly

WordNet sense 5 (characteristic of informal spoken language or conversation):

colloquial

WordNet sense 6 (suited for everyday use):

everyday