The most common and most likely answer to this crossword clue is the 7 letter word OCTETTE
I've seen this crossword clue in Independent
O
C
T
E
T
T
E
More clues leading to the result OCTETTE
- OCTETTE
- Month before letter unmasked group of 8
- Composition improved endlessly after a month
- To some extent, Blunkett etc on about group
- Group with M to take clothing from punter
- Overcharge teetotaller in support group
- Group races alien across green, all turning up
- This number’s set
- 6 animal loses tail and so on turning up inside with a group
- Holt-dweller not quite over ECT treatment group
Buddy explains!

The straight part
We know that "group" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case group = octette.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 OCTETTE mean?
OCTETTE noun- A group or set of eight of something.
- A group of eight musicians performing together.
- A composition for such a group of musicians.
- A byte of eight bits. Abbreviation: o
- A group of three bits, representing any of eight possible values.