Webster's Revised Unabridged Dictionary · 1913

Unstring

Unstring , transitive verb

[1st pref. un- + string.]

1.
To deprive of a string or strings; also, to take from a string; as, to unstring beads.
2.
To loosen the string or strings of; as, to unstring a harp or a bow.
3.
To relax the tension of; to loosen.
Used also figuratively; as, his nerves were unstrung by fear.
His garland they unstring. — Dryden