Run of diamonds for old poet (5)

I believe the answer is:

homer

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'old poet' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for homer that I've seen before include "makes round trip by air" , "Trained pigeon" , "Old Greek epic poet" , "Greek poet - TV's Simpson" , "Greek author; pigeon" .)

I've seen this clue in The Telegraph.

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