Almost secure cover for one who's retired (7)
I believe the answer is:
nightie
'cover for one who's retired' is the definition.
I can't tell whether this definition defines the answer.
'almost secure' is the wordplay.
'almost' becomes 'nigh' (nigh can mean almost or nearly).
'secure' becomes 'tie' (tying is a kind of securing).
'nigh'+'tie'='NIGHTIE'
(Other definitions for nightie that I've seen before include "put on at end of day?" , "Light sleeping gown" , "Lingerie item" , "Woman's bedwear" , "Bedtime attire" .)