The most common and most likely answer to this crossword clue is the 7 letter word TRIOLET
I've seen this crossword clue in The Guardian
T
R
I
O
L
E
T
More clues leading to the result TRIOLET
Buddy explains!

The straight part
We know that "that’s poetic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case that’s poetic = triolet.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TRIOLET mean?
TRIOLET noun- An eight-line poem whose rhyme scheme is ABaAabAB and whose lines are in iambic tetrameter.