blockheads

/B L AA1 K HH EH0 D Z/
noun
  1. 1

    A stupid person.

  2. 2

    A sideshow performer who hammers nails or similar items through his or her nostril into the nasal cavity; human blockhead.

verb
  1. 1

    To perform as a human blockhead.

  2. 2

    To behave in a stupid manner.

Source: https://en.wiktionary.org/wiki/blockhead, https://en.wiktionary.org/wiki/blockheads