Arduous chore, climbing (6,4)

I believe the answer is:

uphill task

I'm a little stuck... Click here to teach me more about this clue!

'climbing' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'arduous chore' is the wordplay.
'arduous' becomes 'uphill' (I've seen this before).
'chore' becomes 'task' (synonyms).
'uphill'+'task'='UPHILL TASK'

Can you help me to learn more?

(Another definition for uphill task that I've seen is " Struggle".)

I've seen this clue in The Daily Express.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.