The most common and most likely answer to this crossword clue is the 6 letter word NOSHED
I've seen this crossword clue in Independent
N
O
S
H
E
D
More clues leading to the result NOSHED
- Next to building in garden, small number tucked in
- Not a single store had food
- Heartily ate without shelter in garden perhaps
- Not a single compiler scoffed
- Not a hint of dyspepsia after she ate,
- Put away, outhouse gone?
- Number with cast had something to eat
- Put away tools left on the lawn for this reason?
- Ate duck with that lady
- Snacked on return to outhouse
Buddy explains!

The straight part
We know that "Heartily ate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case heartily ate = noshed.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 NOSHED mean?
NOSHED verb- (usually with on) To eat a snack or light meal.
- To perform fellatio (on); to blow.