Harry Houdini's pet cats, to be crude (15)
I believe the answer is:
unsophisticated
'be crude' is the definition.
(I've seen this before)
'harry houdini's pet cats' is the wordplay.
'harry' indicates an anagram (harry can mean to attack or spoil).
'houdinis'+'pet'+'cats'='houdinispetcats'
'houdinispetcats' is an anagram of 'UNSOPHISTICATED'.
'to' acts as a link.
(Other definitions for unsophisticated that I've seen before include "straightforward" , "Lacking experience" , "Simple" , "green" , "crude" .)