Graceful creature in river captured by heartless oarsman (3,4)
I believe the answer is:
roe deer
'graceful creature in river captured by heartless oarsman' is the definition.
(I've seen this before)
'river captured by heartless oarsman' is the wordplay.
'river' becomes 'dee' (River Dee).
'captured by' means one lot of letters goes inside another.
'heartless' says to hollow out the word (remove centre letters).
'oarsman' becomes 'rower' ('rower' can be a synonym of 'oarsman').
'rower' with its centre removed is 'roer'.
'dee' inserted inside 'roer' is 'ROE-DEER'.
(Other definitions for roe deer that I've seen before include "Buck perhaps" , "Small graceful woodland animal" , "Graceful creature in river captured by heartless oarsman" , "Hoofed animal(s)" , "Some wildlife" .)