The less bright learner is in worse disarray (6)
I believe the answer is:
slower
'the less bright' is the definition.
I can't judge whether this defines the answer.
'learner is in worse disarray' is the wordplay.
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'is in' is an insertion indicator.
'disarray' indicates anagramming the letters.
'worse' anagrammed gives 'sower'.
'l' put into 'sower' is 'SLOWER'.
Can you help me to learn more?
(Other definitions for slower that I've seen before include "Not so fast!" , "taking longer" , "Less able to understand" , "Being less intelligent" .)