Sheer or downright (8)
I believe the answer is:
absolute
I believe this is a double definition.
'sheer' is the first definition.
(synonyms)
'downright' is the second definition.
(I've seen this before)
(Other definitions for absolute that I've seen before include "Not qualified; total" , "-273.15degC" , "Unrestricted, out-and-out" , "Free from limits, power perhaps" , "Complete, total, without limits" .)