Keep an eye on poetry in Old English (7)
I believe the answer is:
oversee
'keep an eye on' is the definition.
(I've seen this before)
'poetry in old english' is the wordplay.
'poetry' becomes 'verse' (synonyms).
'in' indicates putting letters inside.
'old english' becomes 'oe'.
'verse' inserted within 'oe' is 'OVERSEE'.
(Other definitions for oversee that I've seen before include "guide" , "Disregard" , "Supervise officially" , "Supervise, manage" , "Superintend, manage" .)