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to become loose; to slacken (e.g. rope)
to become less tense; to relax; to let one's guard down
to slacken (e.g. coldness, supervision); to become lax
to become softer (e.g. ground, facial expression); (of ice) to partially melt
to decrease (e.g. speed)
(of a market price) to go down slightly
「弛む」 has another reading with different meanings.
長年使っていて紐が弛んできました。
After years of use, the string has loosened.
警戒心が弛んだ隙を突かれてしまいました。
I was caught off guard when my vigilance loosened.
長年使っていたベルトのバックルが弛んだ。
The buckle of the belt that had been used for years became loose.