资料来源 : Webster's Revised Unabridged Dictionary (1913)

Unclutch \Un*clutch"\, v. t. [1st pref. un- + clutch.]
   1. To open, as something closely shut. ``Unclutch his griping
      hand.'' --Dr. H. More.

   2. (Mech.) To disengage, as a clutch.