Refers to a professional soldier hired to serve in a foreign army, often for financial gain. Neutral term, but can carry a negative connotation depending on context.
He went to the battlefield as a mercenary.
Mercenaries were often used in medieval Europe.
The country hired foreigners as mercenaries.
He has experience fighting as a mercenary in Africa.
義勇兵 is a volunteer who fights out of conviction or patriotism, whereas 傭兵 fights mainly for money.
counter for people
Swiss mercenary; Swiss guard
Compound of 傭 (hire, employ) and 兵 (soldier). The term directly describes a soldier who is employed for pay.