Pleasant cradling head of endearing relative (5)
I believe the answer is:
niece
'relative' is the definition.
(niece is a kind of relative)
'pleasant cradling head of endearing' is the wordplay.
'pleasant' becomes 'nice' (similar in meaning).
'cradling' is an insertion indicator.
'head of' says to take the initial letters.
The initial letter of 'endearing' is 'e'.
'nice' placed around 'e' is 'NIECE'.
(Other definitions for niece that I've seen before include "A sibling's child" , "girl further down the line" , "Family relation" , "Kinswoman" , "Son's cousin" .)