Sportsmen are usually under an enormous amount of pressure, because the slightest failure could compromise their career.

compromise 是动词，由前缀 com-（表示"共同"）和 promise（承诺）组成，原意是"双方互相让步达成协议"。在这里引申为"损害、危及"，指运动员的职业生涯可能因失败而受到负面影响。