Flounder /ˈflaʊn.dɚ/ v. 困难重重;艰苦挣扎;不知所措
meaning: to experience great difficulties or be completely unable to decide what to do or say next
1) 联想:fl- + founder
2) 联想:fl- 扑腾,拍打(fly, flutter) + founder 创始人
e.g. Although his business was a success, his marriage was floundering. 他虽然事业有成,可婚姻却陷入了困境。