A thousand flowers for teachers (7)
I believe the answer is:
masters
'for teachers' is the definition.
(old word for teachers)
'a thousand flowers' is the wordplay.
'a thousand' becomes 'm' (Roman numeral for a thousand).
'flowers' becomes 'asters' (aster is a type of flower).
'm'+'asters'='MASTERS'
(Other definitions for masters that I've seen before include "Artists of consummate skill" , "competition today" , "Higher degree" , "Could be checkers" , "Boys" .)