Manage to show love with poetry and love's ending (7)
I believe the answer is:
Here is my best explanation:
'manage' is the definition.
('oversee' can be a synonym of 'manage')
'love with poetry and love's ending' is the subsidiary indication.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'with' means one lot of letters go next to another.
'poetry' becomes 'verse' ('verse' can be a synonym of 'poetry'**).
'and' means one lot of letters go next to another.
'ending' suggests the final letters.
The last letter of 'love' is 'e'.
'to show' is the link.
(Other definitions for oversee that I've seen before include "Keep an eye on like foreman", "Supervise, monitor", "Supervise officially", "Supervise, control", "Supervise like ganger", "Supervise, manage", "Supervise, keep an eye on", "Invigilate", "Administer" and "Superintend, manage".)