to certain extent or degree
"pretty big"
"pretty bad"
"jolly decent of him"
"the shoes are priced reasonably"
"he is fairly clever with computers"
In a moderate manner.
"She walked moderately down the path to ensure she did not tire herself out before the hike began."
The word moderately comes from the Middle English term moderatly, which was formed by adding the suffix -ly to the adjective moderate. It entered English with the same meaning it holds today, describing something done in a balanced or average way.