The most common and most likely answer to this crossword clue is the 7 letter word SALADIN
I've seen this crossword clue in The Times
S
A
L
A
D
I
N
More clues leading to the result SALADIN
- Sultan's wickedness, imprisoning a boy
- Old sultan’s envy, perhaps, about a young man
- Shame about horrible noise in tank
- Sultan demands healthy food at home
- Old Kurdish leader perhaps leaves home
- Opponent of Richard I leaves home
- A land is devastated by ancient Muslim warrior
- Crusader’s opponent wanting cold meal hot
- Healthy food at home for Lionheart’s foe
- Sultan unfortunately upset — row ensues
Buddy explains!

The straight part
We know that "Old sultan" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old sultan = saladin.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.