Second person said to be a sheep? (3)
I believe the answer is:
ewe
'a sheep?' is the definition.
(a ewe is a female sheep)
'second person said' is the wordplay.
'second person' becomes 'you' (second person pronoun).
'said' shows a homophone (sound like).
'you' is a homophone of 'EWE'.
'to be' acts as a link.
(Other definitions for ewe that I've seen before include "Farm animal" , "Scottish loch" , "Female in a fleece?" , "Source of milk" , "21a [SHEEP]" .)