The most common and most likely answer to this crossword clue is the 6 letter word CHUMMY
I've seen this crossword clue in The Times
C
H
U
M
M
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More clues leading to the result CHUMMY
Buddy explains!

The straight part
We know that "Friendly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case friendly = chummy.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 CHUMMY mean?
CHUMMY noun- A friend; a pal.
- A roommate, especially in a college or university.
- A mixture of (frequently rancid) fish parts and blood, dumped into the water to attract predator fish, such as sharks
- A coarse mould for holding the clay while being worked on a whirler, lathe or manually.
- A boy who works for a chimney sweep.
- Nickname for a person, especially a suspect or criminal.
- Friendly; on, or trying to be on, intimate terms.