Volume of Poe’s — maybe a line shows misprint (7)
I believe the answer is:
literal
'misprint' is the definition.
(printing term for misprinted letter)
'volume of poe's maybe a line' is the wordplay.
'volume of poe's maybe' becomes 'liter' (US spelling of 'litre' - Poe was a US writer).
'line' becomes 'l' (used when specifying particular lines from a poem).
'liter'+'a'+'l'='LITERAL'
'shows' is the link.
(Other definitions for literal that I've seen before include "Actual" , "A tiller (anag.)" , "Not figurative" , "according to specifications" , "without distortion" .)