n. 自大而鲁莽的人, 顽童, 猿

[ noun ]
someone who is unimportant but cheeky and presumptuous
<noun.person>

Jackanapes \Jack"a*napes\, n. [For Jack o' (= of) apes; prop., a
man who exhibits apes.] [Written also {jackanape}.]
1. A monkey; an ape. --Shak.

2. A coxcomb; an impertinent or conceited fellow.

A young upstart jackanapes. --Arbuthnot.