A vigorous exertion or spurt of effort; to rouse oneself and work hard toward a goal (intransitive sense).
受験に向けて最後に奮発して勉強した。
I gave myself one last big push to study for the exam.
チームは優勝を目指して奮発したプレーを見せた。
The team showed spirited play as they pushed for the championship.
To splurge or spend extravagantly (often used as 奮発する): to treat oneself or others by spending more than usual.
誕生日だから奮発していいレストランに行こう。
Since it's my birthday, let's splurge and go to a nice restaurant.
父が奮発して新しいテレビを買ってくれた。
My father splurged and bought a new TV for me.