IPA: /ɪmˈpɑːrʃəl/
KK: /ɪmˈpɑrʃəl/
Not showing favoritism or bias; treating all sides equally and fairly.
The judge was known for being impartial in all of his cases.
Impartial is formed from "im-" (meaning not) and "partialis" (from Latin, meaning partial or biased). The word describes a state of being not biased or favoring one side over another.
Think of 'not' ('im-') being biased or 'partial' — that's why impartial means not favoring one side.