Synonyms for Muff (same or very similar meaning)
WordNet sense 1 (make a mess of, destroy or ruin):
blow, bobble, bollix, botch, bumble, bungle, flub, fluff, fumble, mishandle, spoil, screw up, bodge, bollix up, bollocks up, botch up, louse up, muck up
From the ODE community, based on WordNet
add/edit