* 문 (Moon): This is a common Korean surname, meaning "gate" or "door." It is a very old surname, and there are many famous people with this surname in Korean history.
* 슬 (Seul): This is a less common Korean given name element. Its meaning is a bit ambiguous, but it likely relates to words like "슬픔 (seulpeum)" which means "sadness," or "슬기 (seulgi)" meaning "intelligence" or "wisdom." It's hard to say for sure without more context.
* 연 (Yeon): This is a very common Korean given name element, meaning "lotus" or "connection." It can also symbolize purity and beauty.
Therefore, "Moon Seul Yeon" would mean something like "Moon, the one who is [related to sadness/wisdom], and connected [to something]."
It's important to note: This is a general interpretation, and the exact meaning could vary depending on the specific context and the family's personal interpretation of the name.