나대다

Etymology
Shortening of.

Verb

 * 1)  to act in an unruly manner; to behave outside accepted norms
 * 2)  to be full of oneself; to show off; to act boastfully; to act ostentatiously, especially to show off one's knowledge
 * 1)  to be full of oneself; to show off; to act boastfully; to act ostentatiously, especially to show off one's knowledge