Serious-sounding fellow (6)

I believe the answer is:

ernest

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

'fellow' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for ernest that I've seen before include "- Bevin, twentieth century Labour politician" , "Resent (anag) - man" , "American writer . . . . . . Hemingway" , "fellow" , "A new genre is myth (anag) -- author" .)

I've seen this clue in The Mirror.

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.