Popular races engaging traveller, one not boosted by others (9)

I believe the answer is:

introvert

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

'one not boosted by others' is the definition.
I can't judge whether this definition defines the answer.

'popular races engaging traveller' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'races' becomes 'tt' (Isle of Man Tourist Trophy races).
'engaging' is an insertion indicator.
'traveller' becomes 'rover' (rover is a kind of traveller).
'tt' placed around 'rover' is 'trovert'.
'in'+'trovert'='INTROVERT'

Can you help me to learn more?

(Other definitions for introvert that I've seen before include "Turn inwards" , "one's reserved" , "quiet" , "One who's withdrawn" , "Shy type" .)

I've seen this clue in The Independent.

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.