不一致字

bù yī zhì zì

1. (orthography) inconsistent words (e.g. "through", "bough" and "rough", where "-ough" is not pronounced the same in each case)
2. inconsistent characters (e.g. 流[liu2], 梳[shu1] and 毓[yu4], which are pronounced differently from each other even though they all have the same notional phonetic component)