The most common and most likely answer to this crossword clue is the 6 letter word BLAZED
I've seen this crossword clue in The Guardian
B
L
A
Z
E
D
Buddy explains!

The straight part
We know that "Was furious" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case was furious = blazed.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 BLAZED mean?
BLAZED verb- To be on fire, especially producing bright flames.
- To send forth or reflect a bright light; shine like a flame.
- To be conspicuous; shine brightly a brilliancy (of talents, deeds, etc.).
- To set in a blaze; burn.
- To cause to shine forth; exhibit vividly; be resplendent with.
- (only in the past participle) To mark with a white spot on the face (as a horse).
- To set a mark on (as a tree, usually by cutting off a piece of its bark).
- To indicate or mark out (a trail, especially through vegetation) by a series of blazes.
- To set a precedent for the taking-on of a challenge; lead by example.
- To be furiously angry; to speak or write in a rage.
- To smoke marijuana.
- To blow, as from a trumpet
- To publish; announce publicly
- To disclose; bewray; defame
- To blazon
- Under the influence of marijuana, usually at a relatively high dose.