nybble Definition nybble A nybble is four bits, or half of an eight-bit byte. The term is generally used to refer to the low four bits or the high four bits of a byte. Thus, a byte may be said to have a ``low nyb- ble'' and a ``high nybble''. One nybble encodes one hexadecimal digit. ***** See Also ***** bit, byte, definitions COHERENT Lexicon Page 1