loosen

to loosen a knot; to loosen one's grip / hold on something

I noticed that my seatbelt had gradually loosened during the journey.

At Liberty th’ unfetter’d Captive stands,

And flings the loosen’d Shackles from his Hands.

Immediately my Shackles loosened and fell away of themselves […]

This is an admirable Rule; a Painter ought to have it perpetually present in his Mind and Memory. […] it loosens his hands, and assists his understanding.

[…] Feare looseneth the Belly; because the Heat retiring inwards towards the Heart, the Gutts and other Parts are relaxed;

I had rather lose the battle than that sister

Should loosen him and me.

[…] after the .iiii. day of oure arryuall in Britayne, the eightene shyps that we spake of before, which hadde the horsemen to conuey ouer, loosened from the further hauen with a soft wynd.