The most common and most likely answer to this crossword clue is the 6 letter word GROTTO
I've seen this crossword clue in The Guardian
G
R
O
T
T
O
More clues leading to the result GROTTO
- Rubbish in front of cave
- Cave not entirely unpleasant? Nothing more
- Mostly unpleasant round small cave
- Annoyed about recommendation at first that’s a little hollow
- Underground place, mostly nasty and hot on the inside
- Rubbish to put in fancy hollow?
- Santa's place having rubbish toys? Not half
- Attractive cave reached round river
- Not entirely unpleasant, old cave
- Chamber gets dirt on Blair, his right wing having deserted
Buddy explains!

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 GROTTO mean?
GROTTO noun- A small cave.
- An artificial cavern-like retreat.
- A Marian shrine, usually built in a cavern-like structure.
- A local organization of cavers that typically organizes trips to caves and provides information and training for caving; a caving club.
- (Satanism) A secretive name for a local group of underground Satanists.