The most common and most likely answer to this crossword clue is the 3 letter word JOE
I've seen this crossword clue in The Guardian
J
O
E
More clues leading to the result JOE
Buddy explains!
The straight part
We know that "Ordinary man" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ordinary man = joe.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 JOE mean?
JOE noun- A male; a guy; a fellow.
- Coffee.
- Darling, sweetheart.