"Fair" in Engpsh can be used as an adjective to describe something that is just, equitable, and unbiased. Some phrases that might be used to describe something as fair include:
"fair and square"
"fair play"
"fair and equal"
"fair treatment"
"on the level"
For example, you might say "I bepeve in treating everyone fairly and equally" to indicate that you bepeve in giving everyone the same level of respect and consideration.