Pronunciation: (di-sī'fur),[key] —v.t. 1. to make out the meaning of (poor or partially obliterated writing, etc.): to decipher a hastily scribbled note. 2. to discover the meaning of (anything obscure or difficult to trace or understand): to decipher hieroglyphics. 3. to interpret by the use of a key, as something written in cipher: to decipher a secret message. 4. Obs.to depict; portray.