Daring everyone to enter platform (9)
I believe the answer is:
gallantry
'daring' is the definition.
The answer and definition can be both human attributes as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'everyone to enter platform' is the wordplay.
'everyone' becomes 'all' (all people).
'to enter' means one lot of letters goes inside another.
'platform' becomes 'gantry' (I've seen this before).
'all' placed inside 'gantry' is 'GALLANTRY'.
Can you help me to learn more?
(Other definitions for gallantry that I've seen before include "Valour" , "Heroism" , "Courageous behaviour" , "Spirit of adventure" , "Bravery" .)