The most common and most likely answer to this crossword clue is the 8 letter word MANCIPLE
I've seen this crossword clue in The Daily Telegraph
M
A
N
C
I
P
L
E
Buddy explains!
The straight part
We know that "Steward" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case steward = manciple.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 MANCIPLE mean?
MANCIPLE noun- A person in charge of purchasing and storing food and other provisions in a monastery, college, or court of law.