American wife over 50 having done a runner? (4)
I believe the answer is:
awol
'having done a runner?' is the definition.
(military abbreviation for Absent Without Leave)
'american wife over 50' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'wife' becomes 'w'.
'over' becomes 'o' (cricket abbreviation).
'50' becomes 'l' (roman numeral).
'a'+'w'+'o'+'l'='AWOL'
(Other definitions for awol that I've seen before include "On the lam" , "Absent without leave (abbrev.)" , "Army offence of being missing from duty, briefly" , "Missing without permission" , "Absent without leave (abbr.)" .)