Dead wrong about thin gravy - temperature is changed (8)
I believe the answer is:
adjusted
'is changed' is the definition.
(I've seen this before)
'dead wrong about thin gravy temperature' is the wordplay.
'wrong' is an anagram indicator.
'about' is an insertion indicator.
'thin gravy' becomes 'jus' (jus is a type of gravy. I am not sure about the 'thin' bit.).
'temperature' becomes 't' (abbreviation).
'dead' is an anagram of 'aded'.
'jus'+'t'='just'
'aded' placed around 'just' is 'ADJUSTED'.
Can you help me to learn more?
(Other definitions for adjusted that I've seen before include "Altered slightly or regulated" , "Fixed, adapted or set right" , "Changed to better fit" , "Modified" , "Adapted or regulated" .)