Sign put outside the man's storehouse (9)
I believe the answer is:
thesaurus
'storehouse' is the definition.
(I've seen this in another clue)
'sign put outside the man's' is the wordplay.
'sign' becomes 'taurus' (Taurus is an example).
'put outside' means one lot of letters goes inside another.
'the man's' becomes 'he's' (he's).
'taurus' going around 'hes' is 'THESAURUS'.
(Other definitions for thesaurus that I've seen before include "work we may refer to" , "Reference book" , "Wordy book" , "Book of words with synonyms, antonyms etc" , "Reference work" .)