Very fine cover for armless seats (5)
I believe the answer is:
sofas
'seats' is the definition.
(sofa is a kind of seat)
'very fine cover for armless' is the wordplay.
'very' becomes 'so' (I've seen this in other clues).
'fine' becomes 'f' (abbreviation).
'cover for' suggests removing the centre.
'armless' with its middle taken out is 'as'.
'so'+'f'+'as'='SOFAS'
(Other definitions for sofas that I've seen before include "Lounges" , "Upholstered seats for more than one" , "Furniture" , "Couches" , "Long upholstered seats" .)