Acknowledgement given in Greek view expressed (9)
I believe the answer is:
gratitude
'acknowledgement given' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'greek view expressed' is the wordplay.
I cannot quite see how this works, but
'greek' could be 'gr' (abbreviation for Greek) and 'gr' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
(Other definitions for gratitude that I've seen before include "Feeling of appreciation" , "feeling of obligation" , "A sense of indebtedness and thankfulness" , "Thankfulness and appreciation" , "Appreciation of kindness" .)