Adjective
1. having no known beginning and presumably no end;
"the dateless rise and fall of the tides""time is endless""sempiternal truth"2. of such great duration as to preclude the possibility of being assigned a date;
"dateless customs"3. not bearing a date;
"a dateless letter"4. unaffected by time;
"few characters are so dateless as Hamlet""Helen's timeless beauty"