only once, in Revelation 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 .)

These dictionary topics are from
M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition,
published by Thomas Nelson, 1897. Public Domain, copy freely.