The most common and most likely answer to this crossword clue is the 6 letter word MESSED
I've seen this crossword clue in The Times
M
E
S
S
E
D
Buddy explains!
The straight part
We know that "Ate together" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ate together = messed.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 MESSED mean?
MESSED verb- (transitive, often used with "up") To make untidy or dirty.
- (transitive, often used with "up") To throw into disorder or to ruin.
- To interfere.
- (used with "with") To screw around with, to bother, to be annoying to.
- To take meals with a mess.
- To belong to a mess.
- To eat (with others).
- To supply with a mess.