Herbicide panel's work is unreadable (14)

I believe the answer is:

indecipherable

'is unreadable' is the definition.
(synonyms)

'herbicide panel's work' is the wordplay.
'work' indicates anagramming the letters.
'herbicide'+'panel'='herbicidepanel'
'herbicidepanel' with letters rearranged gives 'INDECIPHERABLE'.

(Another definition for indecipherable that I've seen is " not good for readers".)

I've seen this clue in the Sydney Morning Herald.

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.