Explorer's moggy carrying bad smell (5)
I believe the answer is:
cabot
'explorer's' is the definition.
(I've seen this before)
'moggy carrying bad smell' is the wordplay.
'moggy' becomes 'cat' (I've seen this before).
'carrying' means one lot of letters goes inside another.
'bad smell' becomes 'bo' (informal abbreviation for body odour).
'cat' enclosing 'bo' is 'CABOT'.
(Other definitions for cabot that I've seen before include "One of two explorers" , "famous explorer" , "Italian leader of the 1497 English expedition to the east coast of today's Canada" , "Italian explorer (father or son)" , "John (Giovanni) -, navigator, explored N. America" .)