Language is living and evolves along with understandings. If some people hold different understandings regarding concepts it is not right for them to be held back from updating definitions due to the rigid 'voice of authority' among those publishing books. Books can open the mind, but they are not much help if we are tied to them in a rigid way.

As you can see from the etymology of the word prejudice - prejudice is ultimately a word that means 'prior judgment'.

Bias refers to a similar form of judgement based thought that is closed and that denies aspects of reality as a result.

By noticing that prejudice IS judgement and that bias is essentially similar - we can see something more of the nature of judgements.