The best (5)
'the best' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for second to none that I've seen before include "Incomparable" , "Supreme, best" , "Pre-eminent" , "perfect" , "Outstanding" .)
'the best' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for primo that I've seen before include "... Levi (novelist)" , "Right-hand part in piano duet" , "Duet's lead part (It. first)" , "top player" , "duettist" .)