Undo the ties of:
— They untied the prisoner.

synonyms: unbrace, unlace.

Cause to become loose:
— Untie the knot.

synonyms: loosen, undo.

Roget 750: liberate, free; set free, set clear, set at liberty; render free, emancipate, release; enfranchise, affranchise^†; manumit; enlarge; disband, discharge, disenthrall, disenthral, dismiss; let go, let loose, loose, let out, let slip; cast adrift, turn adrift; deliver etc. 672; absolve etc. (acquit) 970.    unfetter etc. 751, untie etc. 43; loose etc. (disjoin) 44; loosen, relax; unbolt, unbar, unclose, uncork, unclog, unhand, unbind, unchain, unharness, unleash; disengage, disentangle; clear, extricate, unloose.    gain one's liberty, obtain one's liberty, acquire one's liberty etc. 748; get rid of, get clear of; deliver oneself from; shake off the yoke, slip the collar; break loose, break prison; tear asunder one's bonds, cast off trammels; escape etc. 671.    ... show more

Dutch: ontrafelen, losdoen, loskrijgen, losmaken, losnemen