Fastidiously; carefully.
"She folded her laundry nicely, smoothing every crease before placing it in the drawer."
A surname.
"The Nicely family has lived in that neighborhood for three generations."
The word nicely comes from Middle English nycely, which was formed by adding the suffix -ly to the adjective nice. It traveled into modern English with a meaning related to carefulness or precision, distinct from its current association with pleasantness.