Translation guide
To become less careful or vigilant, often after feeling safe or comfortable, leading to potential mistakes or vulnerability.
To stop being cautious or alert, often temporarily, making oneself vulnerable.
The most common and direct equivalent. Used when someone becomes careless and something bad happens as a result.
油断すると失敗するよ。
If you let your guard down, you'll make a mistake.
彼は油断して財布を盗まれた。
He let his guard down and had his wallet stolen.
Literally 'loosen one's spirit/attention'. Implies relaxing mental tension, often after a period of focus or stress.
試験が終わって気を緩めた。
After the exam, I let my guard down.
Literally 'lift one's guard/alert'. More formal and often used in security or military contexts.
敵が去ったので警戒を解いた。
Since the enemy left, they let their guard down.
To lower emotional defenses, allowing oneself to be vulnerable or trusting with others.
Avoid direct translations like ガードを下げる (gādo o sageru). While sometimes used in sports or gaming contexts, it's not natural for everyday situations. Use 油断する or 気を緩める instead.
To open one's heart, trust someone enough to be unguarded. Often used in personal relationships.
彼女に心を許してしまった。
I let my guard down with her.
To release one's wariness or suspicion. Used when someone stops being defensive.
彼の優しい言葉に警戒心を解いた。
I let my guard down at his kind words.