snot-nosed
/ˈsnɒtnəʊzd/adjective
1- informal childish and inexperienced (used as a general term of abuse)〈非正式〉（一般性辱骂用语）幼稚的, 无经验的：
a boy at thirteen is a snot-nosed kid.
13岁的男孩还是乳臭未干的小孩子。
1.1
- (of a person) considering oneself superior; conceited（人）狂妄自大的; 自以为是的：
a snot-nosed snob.
一个自以为是的势利小人。