Quietly being deceptive about working at a trade (6)

I believe the answer is:

plying

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

But I can't explain it at all! Could you help me understand?

(Other definitions for plying that I've seen before include "Travelling a route regularly" , "carrying on" .)

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.