To free (someone or something) from a constraint; (figuratively) to release (something which has been suppressed, such as emotions or objectionable things).
To loosen or undo (something that entangles, fastens, holds, or interlocks).
To relax or slacken (something that clasps or grips, such as the arms or hands).
To become loose or come off.
To free from a constraint.
To release from a pen.