Go west with old man in America on vacation (3,3)
I believe the answer is:
pop off
'go west' is the definition.
(thesaurus)
'with old man in america on vacation' is the wordplay.
'with' means one lot of letters goes inside another.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'man in america' becomes 'pp' (I can't justify this - if you can you should believe this answer much more).
'on vacation' becomes 'off' (off can mean away on holiday).
'o' put within 'pp' is 'pop'.
'pop'+'off'='POP OFF'
Can you help me to learn more?
(Other definitions for pop off that I've seen before include "Leave without warning" , "Go" , "exit" , "Die informally like champagne cork?" , "Die informally to sound of champagne cork?" .)