mishandle
1. [ verb ] make a mess of, destroy or ruin
Synonyms: louse_up spoil fuck_up muck_up foul_up flub mess_up blunder ball_up bobble muff bumble blow fumble bollocks bollocks_up fluff bungle bollix bollix_up screw_up botch_up botch
Examples:

"I botched the dinner and we had to eat out" "the pianist screwed up the difficult passage in the second movement"

Related terms: fail blurt_out blunder spoil bungler fluff ballup screwup
2. [ verb ] manage badly or incompetently
Synonyms: mismanage misconduct
Examples:

"The funds were mismanaged"

Related terms: manage misconduct