Picadors in trouble occurring now and then (8)

I believe the answer is:

sporadic

I'm a little stuck... Click here to teach me more about this clue!

'occurring now and then' is the definition.
I can't tell whether this definition defines the answer.

'picadors in trouble' is the wordplay.
'in trouble' is an anagram indicator.
'picadors' with letters rearranged gives 'SPORADIC'.

Can you help me to learn more?

(Other definitions for sporadic that I've seen before include "Occasional - intermittent" , "infrequent" , "Scattered - irregular" , "Occurring infrequently" , "Isolated; intermittent" .)

I've seen this clue in The Telegraph.

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