Meaning : To certain extent or degree.
Example :
Pretty big.
Pretty bad.
Jolly decent of him.
The shoes are priced reasonably.
He is fairly clever with computers.
Synonyms : fairly, jolly, middling, passably, pretty, reasonably, somewhat
To a degree that exceeds the bounds or reason or moderation.
His prices are unreasonably high.Meaning : With moderation. In a moderate manner.
Example :
He drinks moderately.