Poem for children (7,5)
I believe the answer is:
nursery rhyme
'poem for children' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for nursery rhyme that I've seen before include "Young children's verse" , "Children's poem" , "Traditional verse for children" , "may be used in infant school" , "Poem for children" .)