Suitable primate to cover one in job (8)
I believe the answer is:
apposite
'suitable' is the definition.
(thesaurus)
'primate to cover one in job' is the wordplay.
'primate' becomes 'ape' (I've seen this before).
'to cover' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'in' means one lot of letters goes inside another.
'job' becomes 'post' (post is a kind of job).
'i' placed inside 'post' is 'posit'.
'ape' going around 'posit' is 'APPOSITE'.
(Other definitions for apposite that I've seen before include "Pertinent, well-chosen" , "A pit pose could be to the purpose" , "Appropriate for purpose or occasion" , "Befitting" , "Appropriate, apt" .)