flounder

Synonyms: blunder bobble cast about come apart at the seams drop the ball fall down flop flummox foul up fumble go at backwards go to pieces grope labor lurch make a mess of miss one’s cue muddle plunge pratfall screw up slip up snafu strive stub one’s toe stumble thrash toil toss travail trip up tumble wallow work at

Antonyms: do well succeed