Various staff providing cover for aged (8)
I believe the answer is:
manifold
'various' is the definition.
(thesaurus)
'staff providing cover for aged' is the wordplay.
'staff' becomes 'man' (manning is a kind of staffing).
'providing' becomes 'if' (I've seen this in other clues).
'cover for' says to put letters next to each other.
'aged' becomes 'old' (similar in meaning).
'man'+'if'+'old'='MANIFOLD'
(Other definitions for manifold that I've seen before include "Many and various" , "of numerous parts" , "Various; engine part" , "Diverse like engine part?" , "Multi-functional" .)