Crossword Genius

Book the man's found in house (9)

Ross

I believe the answer is:

thesaurus

'book' is the definition.
(thesaurus is a kind of book)

'the man's found in house' is the wordplay.
'the man's' becomes 'hes' (he's).
'found in' indicates putting letters inside.
'house' becomes 'taurus' (Taurus is an example**).
'hes' put into 'taurus' is 'THESAURUS'.

(Other definitions for thesaurus that I've seen before include "Dictionary" , "Book listing synonyms" , "Volume of synonyms" , "lists?" , "Wordbook" .)

I've seen this clue in The Times.
Want a hint initially instead of a full solution? Install my app