Tree a pig’s tucked into a lot (8)
I believe the answer is:
mahogany
'tree' is the definition.
(I've seen this before)
'a pig's tucked into a lot' is the wordplay.
'pig' becomes 'hog' ('hog' can be a synonym of 'pig').
'tucked into' indicates putting letters inside.
'a lot' becomes 'many'.
'a'+'hog'='ahog'
'ahog' put within 'many' is 'MAHOGANY'.
(Other definitions for mahogany that I've seen before include "Hogmanay? (anag)" , "Type of wood" , "Log" , "Dark wood" , "tree" .)