Meaning:

“行走的” means “walking,” and “荷尔蒙” means “hormone.” A hormone is a chemical substance produced in an endocrine gland and transported in the blood to a specific tissue, on which it exerts a specific effect. This term, coined by Chinese netizens, is used to refer to a man who is so sexy and charming that women get excited or even horny at the sight of him. The term was originally used to describe Zhu Yawen, a Chinese actor who portrayed a bold, fearless hunk in the TV series “Red Sorghum.”

Example:

A: 最近有部美剧很火，叫《空乘危机》。

Zuìjìn yǒu bù měijù hěn huǒ，jiào 《kōngchéng wēijī》。

An American TV series called “The Flight Attendant” is very popular now.

B: 谁演的？

Shuí yǎn de？

Who’s in the show?

A: 女主是凯莉▪库柯，男主我不知道名字，但他就是行走的荷尔蒙。

Nǚzhǔ shì kǎilì kùkē，nánzhǔ wǒ bù zhīdào míngz ，dàn tā ji shì xíngzǒu de héěrméng。

Kaley Cuoco is the heroine, but I don’t know the name of the leading male actor, who is, however, super hot.