Pose to offer word of thanks in love (11)
I believe the answer is:
affectation
'pose' is the definition.
('affectation' can be a synonym of 'pose')
'word of thanks in love' is the wordplay.
'word of thanks' becomes 'ta'.
'in' is an insertion indicator.
'love' becomes 'affection' (affection is a kind of love).
'ta' placed into 'affection' is 'AFFECTATION'.
'to offer' acts as a link.
(Other definitions for affectation that I've seen before include "Show evidence of" , "unnatural appearance" , "retence" , "Deliberate pretence" .)