The most common and most likely answer to this crossword clue is the 8 letter word JAUNDICE
J
A
U
N
D
I
C
E
More clues leading to the result JAUNDICE
Buddy explains!

The straight part
We know that "fever" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fever = jaundice.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does JAUNDICE mean?
JAUNDICE noun- A morbid condition, characterized by yellowness of the eyes, skin, and urine.
- A feeling of bitterness, resentment or jealousy.
- To affect with jaundice; to color by prejudice or envy; to prejudice.