to do (a piece of work) badly and clumsily

blunder, mess up

to make mistakes; do or be wrong

make a mistake; do wrong

to move, walk or act in an uncertain or hesitating manner, from either weakness or fear

stumble, stutter

to make wild and usually useless efforts (as when one is in deep water and unable to swim)

struggle; be in the dark

to calculate (amounts etc) wrongly

make a mistake

to judge (a person, measurement etc) wrongly; form a wrong opinion of (a person, thing)

get the wrong idea

a covering, open at both ends, used to keep the hands warm

bungle