Some wiser monotony for preacher's speech (6)
I believe the answer is:
sermon
'preacher's speech' is the definition.
(speech given by a preacher)
'some wiser monotony for' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'SERMON' can be found hidden inside 'wiser monotony for'.
(Other definitions for sermon that I've seen before include "Pulpit speech" , "Moralising oration" , "Vicar's talk" , "Church address" , "Tedious admonition" .)