Hoot and a half (4)
I believe the answer is:
riot
'hoot and a half' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for riot that I've seen before include "Wild revelry" , "A wild public affray" , "Uprising" , "Violent crowd disturbance" , "Affray, fighting in the streets" .)