Drain out at the lowest point (5)
I believe the answer is:
nadir
'the lowest point' is the definition.
(I've seen this before)
'drain out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'drain' with letters rearranged gives 'NADIR'.
'at' acts as a link.
(Other definitions for nadir that I've seen before include "Low point" , "pits" , "The lowest point of anything" , "You can't sink lower!" , "Very bottom, farthest from zenith" .)