having a relaxed, friendly, or unofficial style, manner, or nature 不拘礼节的,轻松的;友好的;非官方的;非正式的 an informal atmosphere. 友好的气氛。 an informal agreement between the two companies. 两公司间的非正式协定。 ■of or denoting a style of writing or conversational speech characterized by simpler grammatical structures, more familiar vocabulary, and greater use of idioms and metaphors (写作风格,谈话)非正式的,通俗的,口语化的 ■(of dress) casual; suitable for everyday wear (着装)随意的,适合日常穿的 ■(of economic activity) carried on by self-employed or independent people on a small scale, especially unofficially or illegally (经济活动)自发组织的(尤指非官方或非法的)