The most common and most likely answer to this crossword clue is the 5 letter word CADRE
I've seen this crossword clue in The Times
C
A
D
R
E
More clues leading to the result CADRE
- Worry about Democratic campaign group?
- Military unit’s chaplain quietly becoming Conservative
- Caught by publicity about group
- Group of revolutionary activists with duke in charge
- Be concerned about daughter in service unit
- Squad's days in custody
- Worry about daughter in revolutionary group
- Revolutionary group around active Red
- Fighting unit in trouble when duke intervenes
- With business static a dreaded group of activists appear within
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 = cadre.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 CADRE mean?
CADRE noun- A frame or framework.
- The framework or skeleton upon which a new regiment is to be formed; the officers of a regiment forming the staff.
- The core of a managing group, or a member of such a group.
- A small group of people specially trained for a particular purpose or profession.