What does bias mean?

Answer 1

Bias is when someone takes a side for eg: favor ism
Leaning in a particular direction.
Bias is when you're predispositioned towards a certain outcome.

For example: If you ran a test to figure out whether or not smoking was harmful, and you already vehemently believed it did not, your test results would either disregard results unless they favored your outlook, or would be reworded to downplay the evidence you discovered that hurt your previous opinion.

Answer 2

There are more than 70 acronyms for bia. Without additional information or context it is not possible to answer the question.