The most common and most likely answer to this crossword clue is the 7 letter word SERIOUS
I've seen this crossword clue in The Sunday Telegraph
S
E
R
I
O
U
S
More clues leading to the result SERIOUS
- Concerned with component of blood containing iodine — that’s worrying
- Earnest and oddly sweary notes from short people
- Serf is of use — finishes off grave
- Major port in south-east America
- One’s entombed in watery grave
- Setter found in watery grave
- Grave debts following end of dealings with the Queen
- Such trouble arises from boisterous rule breaking
- Important issue or absurd...
- One buried inside watery grave
Buddy explains!
The straight part
We know that "grave" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case grave = serious.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 SERIOUS mean?
SERIOUS adjective- Without humor or expression of happiness; grave in manner or disposition
- Important; weighty; not insignificant
- Really intending what is said (or planned, etc); in earnest; not jocular or deceiving
- (of a relationship) Committed.
- In a serious manner; seriously.