ETYMOLOGY
fancifully from solemn (adj.), after melancholy
EXAMPLE
[Dr. John Beatty to Philip Fithian]
Philadelphia, December 18th, 1772
“… I rode that evening you left me as far as Cormans; being very Solemncholly and somewhat tired, I concluded to stay there all night; and very early next morning breakfasted at Gloucester and got into Philadelphia before Eleven of the clock …”
From: Journal and Letters
By Philip Vickers Fithian, 1900
Lexicophilia 