Do you briefly join a western den of insurance workers? (9)
I believe the answer is:
actuarial
'do you briefly join' is the definition.
I can't judge whether this definition defines the answer.
'a western den of insurance workers?' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
'workers?' could be 'tu' (abbreviation for trade union) and 'tu' is present in the answer.
'insurance' could be 'car' (car insurance is a kind of insurance) and 'car' is located in the leftover letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for actuarial that I've seen before include "risky business" , "Dealing with business figures" , "Calculating risks" , "Relating to insurance calculations" , "Of the work of statisticians who calculate insurance premiums" .)