Teacher in top half of tree, holding out nuts (5)
I believe the answer is:
tutor
'teacher in top' is the definition.
'tutor' can be an answer for 'teacher' (tutor is a kind of teacher). I'm not sure about the 'in top' bit.
'half of tree holding out nuts' is the wordplay.
'half of' means to take half the letters.
'holding' indicates putting letters inside.
'nuts' indicates an anagram (nuts can mean crazy).
'tree' with half the letters taken is 'tr'.
'out' is an anagram of 'uto'.
'tr' placed around 'uto' is 'TUTOR'.
Can you help me to learn more?
(Other definitions for tutor that I've seen before include "School" , "Private instructor" , "Give individual instruction" , "train" , "Master" .)