Out of style (3)
'out of style' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for dated that I've seen before include "Old-fashioned" , "Out of fashion" , "Archaic; took out" , "Pass" , "Met socially by arrangement" .)
(Other definitions for old that I've seen before include "Long in the tooth" , "Former, previous" , "Stale" , "Getting on" , "Senescent" .)