Old woman going round key or island (5)
I believe the answer is:
malta
'island' is the definition.
(Malta is an example)
'old woman going round key' is the wordplay.
'old woman' becomes 'ma' (both can mean someone's mother).
'going round' is an insertion indicator (some letters go around others).
'key' becomes 'alt' (the Alt keyboard button).
'ma' enclosing 'alt' is 'MALTA'.
'or' is the link.
(Other definitions for malta that I've seen before include "Mediterranean island awarded the George Cross" , "Island member of the European Union" , "Mediterranean island republic" , "The capital is Valetta" , "small island" .)