The most common and most likely answer to this crossword clue is the 6 letter word CAVERN
C
A
V
E
R
N
More clues leading to the result CAVERN
- In Africa vernacular term for underground area
- Beware of sailors in underground chamber
- Hollow warning to sailors
- Incomplete nerve agent initially strewn about first underground chamber
- Beware sailors in underground place
- Roughly snubbed sci-fi author’s grot
- Old music club put clergyman back in prison
- Hollow container’s almost bare interior
- Clergyman brought up May to embrace underground space
- Beware of sailors en masse in old Liverpool club!
Buddy explains!

The straight part
We know that "grot" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case grot = cavern.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 CAVERN mean?
CAVERN noun- A large cave.
- An underground chamber.
- To form a cavern or deep depression in.
- To put into a cavern.