Nantoka/제일선jeilseon[제일썬]제일선 (jeilseon) is a Korean word meaning “frontline”.Meanings1frontlinePart of speechnounHanja第一線Related words제일first제일most일one일one일부part일주일one week일월January만일in case십일월November제-je-동일sameness일반the sameStudy Korean with flashcards →