We use fairly as an adverb meaning ‘in a way which is right and just’:
She took her employer to court because she claimed that she hadn’t been treated fairly.
United Nations observers made sure that the election was conducted fairly.
We also use fairly as an adverb of degree before adjectives and adverbs to mean ‘quite, but less than very’:
He’s fairly tall. (He’s quite tall, but not very tall.)
My mother says that her family was fairly poor when she was growing up.
He visits us fairly regularly these days.
Don’t confuse the adjective fair with the adverb fairly:
I think it will be very, very difficult for the unions to negotiate with these companies in a fair way.
Not: … in a fairly way.
I believe everyone should be treated fairly.
Not: … treated fair.
