School meant to order flower part (6)
I believe the answer is:
stamen
'flower part' is the definition.
(I know that stamen is part of androecium)
'school meant to order' is the wordplay.
'school' becomes 'S'.
'to order' is an anagram indicator.
'meant' anagrammed gives 'tamen'.
's'+'tamen'='STAMEN'
(Other definitions for stamen that I've seen before include "Part of a flowering plant" , "Male fertilising organ of flowering plants" , "Pollen-bearing organ of flower" , "Male organ of plant" , "Bit of a bloomer" .)