Crossword Genius

One who works like a horse? (6)

Ross

I believe the answer is:

trojan

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

'one who works' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'a horse?' is the wordplay.
I cannot quite understand how this works, but
'a' could be 'an' and 'an' is present in the answer.
This explanation may well be incorrect...

'like' acts as a link.

Can you help me to learn more?

(Other definitions for trojan that I've seen before include "Native of Troy" , "Native like Helen" , "Of Troy or its people" , "one typically hard-working" , "Hard grafter (from an ancient city?)" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app