unbolt verb.
[ʌn'bǝʊlt] L15.[from UN-2 + BOLT verb2.]1. verb intrans. Of a door: open or unfasten by having the bolt withdrawn.
L15.2. verb trans. & intrans. Draw back the bolt of (a door etc.); unfasten (a door etc.) in this way.
L16.■ B. Chatwin The..man unbolted..the immense baroque doors of the Church. [TahlilGaran] English Dictionary ▲