The most common and most likely answer to this crossword clue is the 4 plus 5 letter word HOLY GRAIL
I've seen this crossword clue in Independent
H
O
L
Y
G
R
A
I
L
More clues leading to the result HOLY GRAIL
- “Great goal” is all you’ll hear a girl raving
- Dancing girl lay behind house, the object of desire
- Vessel found in first part of ‘Hope and Glory’ translated by first rate lecturer
- Go with Hillary to crack Everest?
- Object of search for lost glory in winter fall
- Inexperienced motorist cuts into cyclist, fumbling a girl’s much sought item
- Ambition of flag to capture glory at sea
- Object of quest — go high with Hillary
- Shower with glory, perhaps reaching this elusive target
Buddy explains!
The straight part
We know that "Vessel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vessel = holy grail.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.