Quotation mark (8,5)
I believe the answer is:
inverted comma
'quotation mark' is the definition.
(synonyms)
This is all the clue.
(Other definitions for inverted comma that I've seen before include "In writing, it may open up a quotation" , "Single quote mark" , "Quotation mark" , "Punctuation mark (one of a pair)" , "Singular quote" .)