The most common and most likely answer to this crossword clue is the 6 letter word COOKER
I've seen this crossword clue in Independent
C
O
O
K
E
R
Buddy explains!
The straight part
We know that "appliance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case appliance = cooker.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 COOKER mean?
COOKER noun- A device for heating food, a stove.
- (except in compounds) An appliance or utensil for cooking food.
- A cooking apple.