The Collaborative International Dictionary of English v.0.48:

Deaf-mute \Deaf"-mute`\, n.
   A person who is deaf and dumb; one who, through deprivation
   or defect of hearing, has either failed the acquire the power
   of speech, or has lost it. [See Illust. of Dactylology.]
   [1913 Webster]

         Deaf-mutes are still so called, even when, by
         artificial methods, they have been taught to speak
         imperfectly.
   [1913 Webster] deaf-muteness

WordNet (r) 3.0 (2006):

deaf-mute
    adj 1: lacking the sense of hearing and the ability to speak
           [syn: deaf-and-dumb, deaf-mute]
    n 1: a deaf person who is unable to speak [syn: mute, deaf-
         mute, deaf-and-dumb person]