Ancient ladies snorting crack after noon (4-3)

'ancient' is the definition.
(I've seen this before)

'ladies snorting crack after noon' is the wordplay.
'ladies' becomes 'loo' ('the ladies' is a type of loo or toilet).
'snorting' indicates putting letters inside (snort can mean to ingest through the nose).
'crack' becomes 'gag' (both can mean a joke).
'after' says to put letters next to each other.
'noon' becomes 'n'.
'gag' after 'n' is 'ngag'.
'loo' enclosing 'ngag' is 'LONG-AGO'.