Blithesome, a.
Cheery; gay; merry. The blithesome sounds of wassail gay. Sir W. Scott. -- Blithe"some*ly, adv. -- Blithe"some*ness, n.
Shades of meaning
Fernald has no entry of its own for blithesome; he lists it under happy.
He lists it without comment; the entries above explain its neighbors.