Deliver article to top or bottom level (5)
I believe the answer is:
nadir
'bottom level' is the definition.
'nadir' can be an answer for 'bottom' (I've seen this in another clue). I am not certain of the 'level' bit.
'deliver article to top or' is the wordplay.
'deliver article' becomes 'nadi' (I can't explain this - if you can you should give a lot more credence to this answer).
'to top' means to remove the first letter.
'or' with its first letter taken off is 'r'.
'nadi'+'r'='NADIR'
Can you help me to learn more?
(Other definitions for nadir that I've seen before include "worst-case scenario?" , "Lower one cannot get!" , "extremely low position" , "Drain (anag)" , "pits" .)