Failed to notice (10)
'failed to notice' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for overlooked that I've seen before include "Had in sight" , "Failed to notice" , "Neglected - visible from above" , "allowed to go unpunished?" , "missed" .)
'failed to notice' is the definition.
('ignore' can be a synonym of 'fail to notice')
This is the entire clue.
(Other definitions for ignored that I've seen before include "Paid no heed" , "Passed over" , "Left out in the cold" , "cast aside" , "Turned a blind eye to" .)