I am taken in by a fat Scottish landowner (5)
I believe the answer is:
'scottish landowner' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for laird that I've seen before include "Scottish squire" , "Proprietor" , "Scottish estate-owner" , "Scottish owner of large estate" , "rich Scotsman" .)