The slang term 여사친 (yeosachin) refers to a female friend who is strictly platonic—not a girlfriend.
It’s a combination of:
여 (yeo) → Short for 여자 (yeoja), meaning “woman”
사 (sa) → Short for 사람 (saram), meaning “person”
친 (chin) → Short for 친구 (chingu), meaning “friend”
So, 여사친 literally translates to “female-person-friend”, distinguishing a male friend from a 여친 (yeochin), which means “girlfriend”.
Note the different writing!
여사.. vs. 여자.. 여사친 = platonic female friend, 여자친구 = girlfriend
Example Sentences:
그는 내 여사친일 뿐이야. She’s just my female friend.
여사친이랑 영화 보러 갔어. I went to watch a movie with my female friend.
여사친하고 여행 가는 건 어때? How about going on a trip with your female friend?
The male version of this word is 남사친.