Both Uses of

flourish

in

Things Fall Apart

He would return with a flourish, and regain the seven wasted years.
p. 171.6 *

flourish = showy manner

The over-zealous converts who had smarted under Mr. Brown's restraining hand now flourished in full favour.
p. 185.6 *

flourished = thrived (did well)

Definitions:

(1) (flourish as in: the business is flourishing)
to thrive (grow or develop well)
(2) (flourish as in: dismissed them with a flourish)
a showy gesture

or:

the act of waving -- a hand or an item
(3) (meaning too rare to warrant focus)
In Shakespeare's plays, flourish is often used as a stage direction indicating a specific type of showy gesture: fanfare played by trumpets or other horns to announce the entry or exit of royalty.

Check a comprehensive dictionary for other senses including some that are of interest to musicians.