An adventure or venture — going to unknown places or undertaking exciting, often voluntary experiences.
夏休みに友達と山で小さな冒険をした。
During summer vacation I had a little adventure in the mountains with friends.
彼は世界一周の冒険に出ることを決めた。
He decided to set off on an around-the-world adventure.
子どもたちは庭で冒険ごっこをして遊んでいる。
The children are playing adventure games in the yard.
A risky venture or hazardous attempt — an undertaking unlikely to succeed that involves danger or high risk.
その新規事業は、よく調査せずに始めるとただの冒険に過ぎない。
That new business, if started without proper research, is nothing more than a risky venture.
資金が足りない状態で海外展開するのは冒険的だ。
Expanding overseas without enough funds is a risky move.
彼の計画は冒険心に富んでいるが、現実的とは言えない。
His plan is full of adventurous spirit, but it's not realistic.