Scotsman originally married at Crianlarich (3)
I believe the answer is:
mac
'scotsman' is the definition.
'originally married at crianlarich' is the wordplay.
'originally' says to take the initial letters.
The first letters of 'married at crianlarich' is 'MAC'.
(Other definitions for mac that I've seen before include "PC" , "Overcoat" , "one used in shower?" , "Waterproof raincoat, in short" , "Raincoat (colloq.)" .)