The Collaborative International Dictionary of English v.0.48:

Tongue-tie \Tongue"-tie`\, n. (Med.)
   Impeded motion of the tongue because of the shortness of the
   fraenum, or of the adhesion of its margins to the gums.
   --Dunglison.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tongue-tie \Tongue"-tie`\, v. t.
   To deprive of speech or the power of speech, or of distinct
   articulation.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tongue-tie
    v 1: deprive of speech; "When he met his idol, the young man was
         tongue-tied"