Hard-working time adding lubrication may require thematic contribution (7)

I believe the answer is:

toiling

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

'require thematic contribution' is the definition.
I can't judge whether this definition defines the answer.

'hard-working time adding lubrication' is the wordplay.
'hard-working time' becomes 't' (abbreviation. I am not sure about the 'hard-working' bit.).
'adding' means one lot of letters go next to another.
'lubrication' becomes 'oiling' (I've seen this in another clue).
't'+'oiling'='TOILING'

'may' acts as a link.

Can you help me to learn more?

(Another definition for toiling that I've seen is " Working long and hard".)

I've seen this clue in The Irish Times.

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.