Shoe for one going furtively (7)

I believe the answer is:

sneaker

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

'shoe' is the definition.
(sneaker is a kind of shoe)

I cannot understand how the rest of the clue works.

(Other definitions for sneaker that I've seen before include "Casual shoe" , "Soft shoe" , "Trainer (shoe)" , "Canvas shoe" , "one tending to go unnoticed?" .)

I've seen this clue in The Sun.

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.