Note lack of talk about one displaying toughness (10)
I believe the answer is:
resilience
'toughness' is the definition.
'note lack of talk about one' is the wordplay.
'note' becomes 're' (**).
'lack of talk' becomes 'silence'.
'about' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'silence' placed around 'i' is 'silience'.
're'+'silience'='RESILIENCE'
'displaying' is the link.
(Other definitions for resilience that I've seen before include "flexibility" , "make quick recovery" , "Ability to recover fast" , "Ability to bounce back" , "Ability to withstand criticism" .)