Send single poem, perhaps, accidentally seeming biased (3-5)
I believe the answer is:
one-sided
'biased' is the definition.
(I know that biased can be written as one-sided)
'send single poem perhaps accidentally seeming' is the wordplay.
I cannot quite see how this works, but
'single' could be 'one' (a single thing - only one) and 'one' is located in the answer.
The remaining letters 'sided' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for one-sided that I've seen before include "Unfair or uneven" , "So denied being partisan or unfair" , "Unilateral" , "Unequal like contest between badly matched opponents" , "Unfairly biased" .)