The dictionary’s description of it? (8,7)
I believe the answer is:
definite article
'the' is the definition.
('the' is the definite article in English)
'description of it?' is the wordplay.
'description of' becomes 'definite' (I can't explain this - if you can you should give a lot more credence to this answer).
'it?' becomes 'article' (I've seen this before).
'definite'+'article'='DEFINITE ARTICLE'
'dictionary's' acts as a link.
I am not very happy about this link. It may belong to another bit of the clue.
(Other definitions for definite article that I've seen before include "Maybe the" , "In English, it's always the" , "part of speech" , "Black and white feature in paper" .)