The Collaborative International Dictionary of English v.0.48:
Telephonic \Tel`e*phon"ic\, a. [Cf. F. t['e]l['e]phonique. See Telephone.] 1. Conveying sound to a great distance. [1913 Webster] 2. Of or pertaining to the telephone; by the telephone. [1913 Webster]WordNet (r) 3.0 (2006):
telephonic adj 1: of or relating to telephony; "telephonic connection"