The most common and most likely answer to this crossword clue is the 5 letter word PALLY
I've seen this crossword clue in The Times
P
A
L
L
Y
More clues leading to the result PALLY
Buddy explains!

The straight part
We know that "as a friend may be" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case as a friend may be = pally.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 PALLY mean?
PALLY noun- An affectionate term of address.
- A slightly derogatory and insulting term of address.
- Like a pal; friendly.
- A paladin.