Frequently, in poems (3)
I believe the answer is:
oft
'frequently in poems' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oft that I've seen before include "Frequently in archaic term" , "(In poetry) frequently" , "Old song'... in the stilly night'" , "time and again in literature" , "Frequently (poetic)" .)