Definition of "gladless"

[…] Easter Sunday, for all its traditions, is a gladless day in London. There is positively nothing to do.

1915, Ernest Temple Thurston, The City of Beautiful Nonsense, page 118

For others it has turned the joy and love of praising God into a gladless fulfillment of “their obligation.”

1974, Casimir A. Kucharek, To Settle Your Conscience, page 112