Join and tire agent out (9)
I believe the answer is:
integrate
'join' is the definition.
(I've seen this before)
'tire agent out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'tire'+'agent'='tireagent'
'tireagent' with letters rearranged gives 'INTEGRATE'.
'and' is the link.
(Other definitions for integrate that I've seen before include "Incorporate into the main group" , "Incorporate into the whole" , "Join" , "Get together" , "Combine into a whole, unite" .)