Large retail organisation, to be exact (7)
I believe the answer is:
literal
'be exact' is the definition.
(similar in meaning)
'large retail organisation' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'organisation' indicates an anagram.
'retail' anagrammed gives 'iteral'.
'l'+'iteral'='LITERAL'
'to' is the link.
(Other definitions for literal that I've seen before include "Unimaginative" , "Accurate and unexaggerated" , "Taking words in their most basic sense" , "Actual" , "According to the letter" .)