Crossword Genius

On the subject of actors, is dull (8)

Ross

I believe the answer is:

overcast

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

'is dull' is the definition.
(as in dull weather)

'on the subject of actors' is the wordplay.
'on' becomes 'over' (over can mean on top of).
'the subject of actors' becomes 'cast' (I can't justify this - if you can you should believe this answer much more).
'over'+'cast'='OVERCAST'

Can you help me to learn more?

(Other definitions for overcast that I've seen before include "State of the sky when it is covered by clouds" , "(Of skies) grey" , "Gloomy like cloudy sky" , "less than fine" , "(Of weather) cloudy, dull" .)

I've seen this clue in the Evening Standard.
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.