Defer start of shopping trip around Spar (8)
I believe the answer is:
bowsprit
'spar' is the definition.
(bowsprit is a kind of spar)
'defer start of shopping trip around' is the wordplay.
'defer' becomes 'bow' ('bow' can be a synonym of 'defer').
'start of' indicates taking the first letters.
'around' is an anagram indicator.
The first letter of 'shopping' is 's'.
'trip' with letters rearranged gives 'prit'.
'bow'+'s'+'prit'='BOWSPRIT'
(Other definitions for bowsprit that I've seen before include "Spar projecting from front of a boat" , "Projecting spar at front of sailing ship" , "Spar projecting from the front of a sailing vessel" , "See component of boat" .)