It's well-timed for ten, poor, up unexpectedly (9)
I believe the answer is:
opportune
'it's well-timed' is the definition.
(similar in meaning)
'ten poor up unexpectedly' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'ten'+'poor'+'up'='tenpoorup'
'tenpoorup' anagrammed gives 'OPPORTUNE'.
'for' acts as a link.
(Other definitions for opportune that I've seen before include "in place" , "Especially convenient" , "Timely, advantageous moment" , "Of time, suitable or favourable" , "Appropriate" .)