This is keeping nothing for the lions (6)
I believe the answer is:
heroes
'the lions' is the definition.
The definition and answer can be both people as well as being plural nouns.
Perhaps you can see an association between them that I can't see?
'this is keeping nothing' is the wordplay.
'this is' becomes 'here's' (both can be used to point out someone or something).
'keeping' means one lot of letters goes inside another (some letters kept inside).
'nothing' becomes 'O' (looks like zero - 0).
'heres' enclosing 'o' is 'HEROES'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for heroes that I've seen before include "Cavaliers" , "Brave people" , "Men of courage, chief characters in plays" , "Men of distinguished bravery and strength" , "Very brave men" .)