Free article rising from the very bottom (5)
I believe the answer is:
nadir
'the very bottom' is the definition.
(I've seen this in another clue)
'free article rising' is the wordplay.
'free' becomes 'rid' (to be free of something is to be rid of it).
'article' becomes 'an' (indefinite article).
'rising' shows that the letters should be reversed in order (in a down clue, letters go up).
'rid'+'an'='ridan'
'ridan' reversed gives 'NADIR'.
'from' acts as a link.
(Other definitions for nadir that I've seen before include "Drain to lowest level" , "You can't sink lower!" , "Lowest point, or time of deepest depression." , "Drain (anag)" , "Given lowest place" .)