Free article turned up low point (5)
I believe the answer is:
nadir
'low point' is the definition.
(I've seen this before)
'free article turned up' is the wordplay.
'free' becomes 'rid' ('rid' can be a synonym of 'free'**).
'article' becomes 'an' (indefinite article).
'turned up' is a reversal indicator.
'rid'+'an'='ridan'
'ridan' in reverse letter order is 'NADIR'.
(Other definitions for nadir that I've seen before include "Drain into the lowest point (5)" , "You can't sink lower!" , "Low-water mark" , "Very bottom, farthest from zenith" , "Point of greatest despair" .)