To flop around as a fish out of water.
To make clumsy attempts to move or regain one's balance.
Robert yanked Connie's leg vigorously, causing her to flounder and eventually fall.
To act clumsily or confused; to struggle or be flustered.
He gave a good speech, but floundered when audience members asked questions he could not answer well.
To be in serious difficulty.
The act of one who flounders; a clumsy struggle.