Beat the most easily beaten (5)
I believe the answer is:
worst
'beat' is the definition.
(worsting is a kind of beating)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for worst that I've seen before include "the pits" , "Beat" , "Lowest of the low" , "Make mincemeat of" , "Most unpleasant" .)