with all one's might; wholeheartedly
Colloquial variant of 思いっきり, used adverbially to mean doing something with full effort or without holding back.
See also: 思いっきり
I ran as hard as I could and got really tired.
Colloquial noun use, often in the phrase 思いっきしをつける (to make up one's mind, to resign oneself). Equivalent to 思いっきり as a noun.
See also: 思いっきり
Let's have a blast today!
I made up my mind and decided to quit my job.
Ateji-like spelling using 切; less common and may be considered non-standard.
Colloquial contraction of 思いっきり (omoikkiri), where the final り (ri) is replaced by し (shi), a common sound shift in casual speech.