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to one's heart's content; as much as one wants; as hard as one can; with all one's strength; to the best of one's ability; to the utmost; with determination; hard; heavily
resolution; decisiveness; determination; resignation
思いっきり走って気分がすっきりした。
I ran with all my might and felt refreshed.
休日は思いっきり遊びたいですね。
I want to play to my heart's content on holidays.
カラオケで思いっきり歌いたいな。
I want to sing with all my heart at karaoke.