The most common and most likely answer to this crossword clue is the 7 letter word KINGPIN
I've seen this crossword clue in The Sunday Telegraph
K
I
N
G
P
I
N
More clues leading to the result KINGPIN
- Relations at home hugging doctor, most important person
- Bigwig’s family at home, welcoming GP
- Leader drunk pink gin
- Family doctor at home is number one in team
- Civil rights campaigner to nail head of syndicate?
- Family doctor at home for VIP
- Family doctor at home is essential person
- Key member of group appearing in shocking pink
- Relative gets doctor in for most important person
- Pink gin ordered for a VIP
Buddy explains!

The straight part
We know that "Key member of group" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case key member of group = kingpin.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 KINGPIN mean?
KINGPIN noun- (motorized vehicles) The axis around which steered wheels pivot; a bolt that holds the axis in place—a kingbolt.
- The pin at the centre of the triangle of bowling pins (originally the tallest pin in kayles). Sometimes also the headpin at the apex.
- The most important person in an undertaking or organization.
- The bolt holding together the truck of a roller skate or skateboard.