Ambassador flees northeastern ground for Turkey? (10)
I believe the answer is:
nonstarter
'turkey?' is the definition.
(turkey can mean a flop or failure)
'ambassador flees northeastern ground' is the wordplay.
'ambassador' becomes 'HE' (His or Her Excellency).
'flees' suggests deleting specific letters.
'ground' indicates an anagram ('grind' the letters into a new form).
'northeastern' with 'he' removed is 'nortastern'.
'nortastern' anagrammed gives 'NONSTARTER'.
'for' is the link.
(Other definitions for nonstarter that I've seen before include "Someone who is never going to succeed" , "Unviable thing" , "One who doesn't even begin" , "Hopeless idea" , "unfeasible idea" .)