Quieten down when suitably seated (6)
I believe the answer is:
sedate
'quieten' is the definition.
Although both the answer and definition are verbs in their base form, I cannot understand how they can define each other.
'down when suitably seated' is the wordplay.
'seated' anagrams to 'SEDATE'.
But, I am not sure how this is indicated.
Can you help me to learn more?
(Other definitions for sedate that I've seen before include "Tranquilise" , "Decorous" , "Staid; put to sleep" , "Unexciting" , "Quiet and dignified" .)