The most common and most likely answer to this crossword clue is the 6 letter word SCHLEP
I've seen this crossword clue in The Guardian
S
C
H
L
E
P
More clues leading to the result SCHLEP
- That is to say, arranged help for arduous trek
- At first, servant can help out and pull something, heavily
- Some way to go with two noughts missing from school record
- Dropped off, mainly outside church, in drag
- Tramp helps out around college
- Getting in Catholic helps out 26 – difficult procedure
- School hop’s not a difficult journey
- Carry school record about learner
- Criminal helps to smuggle cocaine in arduous journey
Buddy explains!

The straight part
We know that "arduous trek" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case arduous trek = schlep.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 SCHLEP mean?
SCHLEP noun- A long or burdensome journey.
- A boring person, a drag; a good-for-nothing person.
- A sloppy or slovenly person.
- A “pull” or influence.
- To carry, drag, or lug.
- To go, as on an errand; to carry out a task.
- To act in a slovenly, lazy, or sloppy manner.