Elevate no prow of boat in middle of Henley (7)
I believe the answer is:
ennoble
'elevate' is the definition.
(ennobling is a kind of elevating)
'no prow of boat in middle of henley' is the wordplay.
'prow of' indicates taking the first letters.
'in' is an insertion indicator.
'middle of' means to look at the middle letters.
The middle of 'henley' is 'enle'.
The first letter of 'boat' is 'b'.
'no'+'b'='nob'
'nob' going inside 'enle' is 'ENNOBLE'.
(Other definitions for ennoble that I've seen before include "Glorify - raise to the peerage" , "Elevate to knighthood" , "Glorify - confer honour upon" , "Aggrandise" , "Bestow peerage on" .)