lose one's way [bearings]
道に迷う,途方にくれる
lose [regain] one's wits
理性を失う[取り戻す]
lose one's zest for study
勉強の興味を失う
lose sight of the big(ger) picture
大局を見失う
lose the ability to bestow membership
会員資格を与える力を失う
lose the fight for existence
生存競争に負ける
lose the game to the opponent
相手に試合で負ける
lose the thread of a story
話の筋がわからなくなる
lose the vote
選挙権を失う
lose the war
戦争に負ける