Token given back by foreign oilman (7)
I believe the answer is:
nominal
'token' is the definition.
(I know that token can be written as nominal)
'given back by foreign oilman' is the wordplay.
'back' says to take the final letters (the letter at the back).
'by' means one lot of letters go next to another.
'foreign' is an anagram indicator (foreign order of the letters).
The last letter of 'given' is 'n'.
'oilman' anagrammed gives 'ominal'.
'n'+'ominal'='NOMINAL'
(Other definitions for nominal that I've seen before include "Minor" , "Theoretical - token" , "In name only or token payment" , "Token - lion man (anag)" , "In name only, like face value of coin" .)