This uses a combination of deletion and container techniques - deletion removes outer letters from a word, and container puts one word inside another.
Look for a word meaning 'flair' and remove its outer letters (making it 'boundless'), then put this inside a word for 'coaches'.
Answer: BUSINESSES | Take 'finess' (FINESSE meaning 'flair' with outer letters F and E removed to make it 'boundless'), and put it inside BUSES (coaches) to get BUS-INESS-ES = BUSINESSES