The most common and most likely answer to this crossword clue is the 9 letter word ASPARTAME
I've seen this crossword clue in The Guardian
A
S
P
A
R
T
A
M
E
More clues leading to the result ASPARTAME
- A box with insipid artificial sweetener
- Sweetener when wise man loses head over rotten meat
- Sweetener — because some in the morning needing energy
- Like normal, bland sweetener
- It’s sweet that a fight gets under control
- Food additive in a box ruined meat
- After a dispute, subdue with sweetener
- A fight, not vicious – that’s sweet
- A corresponding housing area that’s sweet
- That’s sweet, writing “Thanks Radler” on a box
Buddy explains!
The straight part
We know that "that’s sweet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case that’s sweet = aspartame.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 ASPARTAME mean?
ASPARTAME noun- An artificial sweetener, the methyl ester of a dipeptide formed from aspartic acid and phenylalanine, used in many processed foods and beverages.