noun
adventure lover; adventurer
A somewhat rough, masculine term for someone who loves adventure. Often used in a lighthearted or self-deprecating way.
彼は根っからの冒険野郎だ。
He's a born adventure lover.
冒険野郎の俺には、この旅が最高だ。
For an adventure junkie like me, this trip is the best.
冒険家 is a more neutral, formal term for an adventurer or explorer, while 冒険野郎 is casual and carries a rough, masculine, or playful tone.
Compound of 冒険 (adventure) and 野郎 (guy, fellow). The exact origin is uncertain, but it likely emerged as a colloquial, slightly rough expression for an adventure enthusiast.