名詞 informality:

1. a manner that does not take forms and ceremonies seriously
2. freedom from constraint or embarrassment
   同義詞：ease

1. Characterized by careless ease or informality; casual.
   漫不經(jīng)心的以漫不經(jīng)心或隨便態(tài)度為特點的; 漠不關(guān)心的

in.for.mal.i.ty

n.（名詞）
【復(fù)數(shù)】 in.for.mal.i.ties
The state or quality of being informal.
非正式：不正式的狀態(tài)或品質(zhì)
An informal act.
不正式的舉動