Old bird meets an inexperienced driver outside (8)
I believe the answer is:
external
'outside' is the definition.
(synonyms)
'old bird meets an inexperienced driver' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'bird' becomes 'tern' (tern is a kind of bird).
'meets' means one lot of letters go next to another.
'an' becomes 'a'.
'inexperienced driver' becomes 'l' (as in L-plates for learner drivers).
'ex'+'tern'+'a'+'l'='EXTERNAL'
(Other definitions for external that I've seen before include "Belonging to the outside" , "Coming from outside" , "abroad" , "Relating to the outside" , "Surface" .)