The most common and most likely answer to this crossword clue is the 6 letter word HOBNOB
I've seen this crossword clue in The Daily Telegraph
H
O
B
N
O
B
More clues leading to the result HOBNOB
- Socialise with the exalted King out of Aga’s control?
- Associate with tramp holding new book
- Mix with tramps: not very big important person
- Biscuit mix
- To socialise, tramp hugs knight and bishop
- Cooker turned on, first of bowls to mix
- Associate reported control switch for stove?
- Toff’s after top of range? Hang about!
- Mix with number in endless activity
- Head of house, recent pupil and Head mix informally
Buddy explains!

The straight part
We know that "associate" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case associate = hobnob.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 HOBNOB mean?
HOBNOB noun- A toast made while touching glasses together.
- A drinking together.
- An informal chat.
- To drink together.
- To associate with in a friendly manner, often with those of a higher class or status.
- To have or have not; to give or take.
- To toast one another by touching glasses.
- On friendly terms; in friendly association.
- At random; at a venture; hit and miss.