to make ugly
"The harsh wind seemed unfair, turning her once smooth cheeks into rough maps of wrinkles."
not beautiful; uncomely; unattractive
"The old house was so unfair that no neighbor would want to buy it."
In plain English: Unfair means treating someone badly by not following the same rules as everyone else.
"The referee called an unfair penalty against our team."
The word unfair originally meant ugly or unattractive when it entered Middle English from Old English. It traveled into modern usage with its current sense of injustice rather than physical appearance.