North American food wife leaves as snack (5)
I believe the answer is:
nacho
'snack' is the definition.
(I know that nacho is a type of tortilla chip)
'north american food wife leaves' is the wordplay.
'north american' becomes 'na'.
'food' becomes 'chow' (chow can informally mean food).
'wife' becomes 'w' (abbreviation).
'leaves' is a deletion indicator.
'chow' with 'w' taken out is 'cho'.
'na'+'cho'='NACHO'
'as' acts as a link.
(Other definitions for nacho that I've seen before include "part of a snack?" , "Tortilla crisp" , "Piece of tortilla served with sauce" , "Small piece of tortilla with a topping" , "kind of chip" .)