Fail to remember Mark out to get American to ignore local (4,1,5)
I believe the answer is:
draw a blank
'fail to remember' is the definition.
('draw a blank' can be a synonym of 'fail to remember')
'get american to ignore local' is the wordplay.
'get' becomes 'draw' ('draw' can be a synonym of 'get').
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'to ignore local' becomes 'blank' (I can't explain this - if you can you should believe this answer much more).
'draw'+'a'+'blank'='DRAW A BLANK'
'mark out to' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for draw a blank that I've seen before include "elicit no successful response" , "Be unlucky in raffle" , "Get no result" , "Get no successful response" , "lucky in Russian roulette" .)