Cunning wife and one large Yankee (4)
I believe the answer is:
wily
'cunning' is the definition.
(I know that cunning can be written as wily)
'wife and one large yankee' is the wordplay.
'wife' becomes 'w'.
'and' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'large' becomes 'L' (eg in clothes sizes).
'yankee' becomes 'Y' (phonetic alphabet: alpha, bravo, charlie etc.).
'w'+'i'+'l'+'y'='WILY'
(Other definitions for wily that I've seen before include "Skilled at gaining an advantage by deceit" , "Fly" , "Shrewd" , "Cunning; foxy" , "'Crafty, cunning (4)'" .)