Last of meat, dog eating it — that's grand! (8)
I believe the answer is:
'grand' is the definition.
('thousand' can be a synonym of 'grand')
'last of meat dog eating it' is the wordplay.
'last of' indicates one should take the final letters.
'dog' becomes 'hound' (hound is a kind of dog**).
'eating' means one lot of letters goes inside another.
'it' becomes 'sa' (old-fashioned abbreviation for sex appeal).
The final letter of 'meat' is 't'.
'hound' placed around 'sa' is 'housand'.
'that's' is the link.
(Other definitions for thousand that I've seen before include "Ten hundreds" , "a fair amount?" , "Numeric value of kilo" , "M or K" , "Figure" .)