Take badly even the least upset! (5)
I believe the answer is:
steal
'take' is the definition.
(stealing is a kind of taking)
'least upset' is the wordplay.
'upset' indicates an anagram.
'least' is an anagram of 'STEAL'.
'badly even the' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for steal that I've seen before include "Whip" , "Take without permission" , "Take illegally" , "Make off with" , "Creep" .)