testicular fortitude
解释】中文意思就是勇气、胆量（balls, guts, intestinal fortitude, Having balls to do something.）
例句：
He lacked the testicular fortitude to stand up to his boss.
他没有勇气反抗他老板。
He doesn't have the testicular fortitude to challenge me to a fight!
他没有胆量和我斗！
来源:恒星英语学习网-口语频道