Two chaps are foreign (7)
I believe the answer is:
russian
'foreign' is the definition.
Although both the answer and definition are adjectives, I don't see how one could define the other.
'two chaps' is the wordplay.
'two chaps' means two substitutions for 'chap'.
'chap' becomes 'russ' ().
'chap' becomes 'ian' (man's name).
'russ'+'ian'='RUSSIAN'
'are' is the link.
Can you help me to learn more?
(Other definitions for russian that I've seen before include "Slavonic tongue" , "Putin's language" , "Type of doll, dressing, or roulette" , "Native of Moscow, say" , "Countryman" .)