Large raid carried out by landowner (5)
I believe the answer is:
laird
'landowner' is the definition.
(Scottish term for a landowner)
'large raid carried out' is the wordplay.
I cannot quite understand how this works, but
'large' could be 'l' (eg in clothes sizes) and 'l' is found in the answer.
an anagram of 'raid' is 'aird' which is within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'by' acts as a link.
Can you help me to learn more?
(Other definitions for laird that I've seen before include "Big landowner" , "rich Scotsman" , "He's landed in Scotland" , "Man owning land" , "Scot. landowner" .)