hoot

Concise Oxford English Dictionary © 2008 Oxford University Press:
hoot/huːt/

▶noun

• 1 a low musical sound made by many kinds of owl.

  ■ a raucous sound made by a horn, siren, etc.

• 2 a shout of scorn or disapproval.

• 3 an outburst of laughter.

  ■ (a hoot) informal an amusing person or thing.

▶verb

• 1 make or cause to make a hoot.

• 2 (hoot something down) express loud scornful disapproval of something.

– phrases
not care (or give) a hoot (or two hoots) informal not care at all.

– origin ME: perh. imitative.