The unusually stern needs of affection (10)
I believe the answer is:
tenderness
'affection' is the definition.
(I know that affection can be written as tenderness)
'the unusually stern needs' is the wordplay.
'the unusually' indicates an anagram.
'stern'+'needs'='sternneeds'
'sternneeds' is an anagram of 'TENDERNESS'.
'of' acts as a link.
(Other definitions for tenderness that I've seen before include "Heart" , "Gentle quality" , "Gentleness, sensitivity" , "Compassion" , "sore?" .)