Personal assistants wear ID (8)
I believe the answer is:
passport
'id' is the definition.
(passport is a type of identification)
'personal assistants wear' is the wordplay.
'personal assistants' becomes 'pas' (I can't explain this - if you can you should give a lot more credence to this answer).
'wear' becomes 'sport' (sport can mean to wear or display on one's person).
'pas'+'sport'='PASSPORT'
Can you help me to learn more?
(Other definitions for passport that I've seen before include "Official document required for international travel" , "you might need Visa with this" , "Official document required for foreign travel" , "Travel doc" , "Traveller's aid" .)