mercenary
Definition
Motivated by a desire for money or other personal gain rather than loyalty or principle; a professional soldier hired to serve in a foreign army.
日本語 金銭的利益や個人的利益ではなく、忠誠心や原則によって動かされることなく、外国軍に仕えるために雇われたプロの戦士。
Example
"He was criticized for his mercenary attitude toward his career choices."