The most common and most likely answer to this crossword clue is the 10 letter word CONNECTION
I've seen this crossword clue in Independent
C
O
N
N
E
C
T
I
O
N
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 CONNECTION mean?
CONNECTION noun- The act of connecting.
- The point at which two or more things are connected.
- A feeling of understanding and ease of communication between two or more people.
- An established communications or transportation link.
- A transfer from one transportation vehicle to another in scheduled transportation service
- A kinship relationship between people.
- An individual who is related to oneself, through either family or business.
- A set of sets that contains the empty set, all one-element sets for any element that is included in any of the sets, and the union of any group of sets that are elements where the intersections of those sets is non-empty.
- Coherence; lack of disjointedness
- The description for a Methodist denomination as a whole, as opposed to its constituent churches, circuits, districts and conferences.
- Sexual intercourse