No term arranged for teacher (6)
I believe the answer is:
mentor
'teacher' is the definition.
(a mentor is a teacher or guide)
'no term arranged' is the wordplay.
'arranged' indicates anagramming the letters (letters rearranged).
'no'+'term'='noterm'
'noterm' with letters rearranged gives 'MENTOR'.
'for' acts as a link.
(Other definitions for mentor that I've seen before include ""Guide, philosopher, and friend"" , "Train" , "Wise and trusted guide and advisor" , "Merton (anag.)" , "A trusted adviser or teacher" .)