1) Alphabetic character 2) Letter 3) Letter of the alphabet 4) Polyphonic letter 
many-stringed instrument like a lute
• (n.) A character or vocal sign representing more than one sound, as read, which is pronounced red.
Pol'y·phone noun A character or vocal sign representing more than one sound, as read , which is pronounced rēd or rĕd . 
[n] - a letter that has two or more pronunciations
polyphone 1. A large kind of musical box, driven by clockwork or by hand, and capable of playing any tune when the corresponding perforated disk is inserted. 2. A written character having more than one phonetic value; a letter or other symbol which stands for different sounds.
polyphonic letter noun a letter that has two or more pronunciations; ``c` is a polyphone because it is pronounced like `k` in `car` but like `s` in `cell``