The most common and most likely answer to this crossword clue is the 4 letter word LEES
I've seen this crossword clue in The Guardian
L
E
E
S
More clues leading to the result LEES
- Small section of notable estate remains
- Deposit five hundred away from city
- The worst part? General Grievous’s close
- River has sediment
- What’s left at the bottom of shelter close to Calais
- Son’s after a quarter deposit
- What’s left of Bruce?
- What will have settled down in shelter on top of straw
- The last of the wine
- Shelters the worst parts
Buddy explains!

The straight part
We know that "What’s left at the bottom" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what’s left at the bottom = lees.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 LEES mean?
LEES noun- The sediment that settles during fermentation of beverages, consisting of dead yeast and precipitated parts of the fruit.
- A protected cove or harbor, out of the wind.
- The side of the ship away from the wind.
- A sheltered place, especially a place protected from the wind by some object; the side sheltered from the wind (see also leeside); shelter; protection.