Lord's day
only once, in Rev. 1:10, was in the early Christian ages used to
denote the first day of the week, which commemorated the Lord's
resurrection. There is every reason to conclude that John thus
used the name. (See SABBATH ¯T0003170.)
Bibliography Information Easton, Matthew George. M.A., D.D., "Biblical Meaning for 'Lord's day' Eastons Bible Dictionary". bible-history.com - Eastons; 1897.