unlatching

from The Collaborative International Dictionary of English v.0.48

Unlatch \Un*latch"\, v. i. [imp. & p. p. {Unlatched}; p. pr. &
   vb. n. {Unlatching}.] [1st un- + latch.]
   To open or loose by lifting the latch; as, to unlatch a door.
   [1913 Webster]