Does 馬脚 (마각) mean "horse's foot" or "horse's leg"?

 ANSWER: Well, in Korea, 馬脚 (마각) means "horse's (馬) leg (脚)," but in China, it means "a horse's foot" or "hoof," though there seems to be some confusion since 脚 (각) can mean both "leg" and "foot" in certain regions of China.

I have read, however, that in Mandarin Chinese, 脚 (각) is usually used to mean "foot" or "feet," such as in 小脚 (소각), which literally means "small (小) feet (脚)," and 大脚 (대각), which literally means "big (大) feet (脚)." In China, the word 小脚 (소각) refers to "bound feet," feet that have been deformed by the old Chinese practice of binding women's feet to make them look smaller. Women with small feet were considered to be more beautiful in ancient China. And the word 大脚 (대각) refers to "naturally formed feet," which apparently were considered to be ugly for a woman.

There seems to be two Chinese words for "foot-binding." One is 裹脚 (과각) and the other is 纏足 (전족) and both of them literally mean "to wrap or package (裹/纏) feet (脚/足)." The Chinese character 足 (족) can also mean "foot" and is the character that Koreans prefer to use for "foot." So, Koreans usually use the Sino-Korean word 전족 (纏足) to refer to "foot-binding."

Anyway, the idiom 마각을 드러내다 literally means "to show or expose horse feet" or "a horse foot" but is used to mean "to reveal one's true character," seemingly in a negative way. So, 마각 (馬脚) can mean either "horse feet" or "one's true character."

I have read that the expression 마각을 드러내다 comes from a story about the wife of the founder of China's Ming Dynasty. Her family name was supposedly 馬 (마), which is also the character used to mean "horse." Ms. Ma supposedly had "big feet" (大脚), meaning that her feet had not been bound and deformed when she was a child. Ms. Ma was ashamed of her unbound feet because only ugly women had unbound feet in ancient China. Therefore, Ms. Ma always tried hide her "big feet," probably by wearing long gowns. However, one day while getting out of a carriage, Ms. Ma's "big feet" were exposed, revealing her secret or "true character" to the public, which supposedly caused people to start referring to "unbound feet" as 馬脚 (마각).

However, the story does not make sense to me. First, why would the founder of the Ming Dynasty marry a woman with "big feet"? Second, feet that have been deformed by binding look more like "horse feet" than feet that are naturally formed. So, I think that Ms. Ma probably had bound feet, not unbound feet, and that on that day she forgot to put on her fancy shoes before getting out of her carriage, thereby exposing her deformed "horse feet" to the public.