The most common and most likely answer to this crossword clue is the 6 letter word LEGMAN
I've seen this crossword clue in Financial Times
L
E
G
M
A
N
More clues leading to the result LEGMAN
Buddy explains!
The straight part
We know that "errand boy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case errand boy = legman.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 LEGMAN mean?
LEGMAN noun- (originally United States) A person hired to carry out errands or (often) menial tasks, frequently requiring travel from place to place; an errand boy or errand girl, a runner.
- (originally United States) A reporter who frequently travels to conduct research, interview witnesses, etc., and then conveys the information to a rewriteman who writes up the story.