Not-Nice Slang for a Stupid or Eccentric Person

This page is the CodyCross answer for the clue below from Amusement Park, Group 206, Puzzle 2 (Historical Reproduction).

Question is: Not-Nice Slang for a Stupid or Eccentric Person

and the answer is: DINGBAT

Word Meaning:

DINGBAT — (informal) A silly, crazy or stupid person.

Definitions from Wiktionary.