Tucked away (3)
'tucked away' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ate that I've seen before include "Consumed food" , "Bolted" , "Tea (anag.)" , "mischief-maker" , "upset > Greek goddess" .)
(Other definitions for unseen that I've seen before include "Not perceived or observed" , "Invisible or not observed" , "Lurking" , "not processed by pupils?" , "not exercising pupils?" .)