Webster’s Revised Unabridged Dictionary · 1913
Sadly
Sad′ly, adv. 1. Wearily; heavily; firmly. [Obs.]
In go the spears full sadly in arest. Chaucer.
2. Seriously; soberly; gravely. [Obs.]
To tell thee sadly, shepherd, without blame Or our neglect, we lost her as we came. Milton.
3. Grievously; deeply; sorrowfully; miserably. "He sadly suffers in their grief." Dryden.