80%RatingSave Gender Masculine Usage Korean Scripts 일성(Korean Hangul) 日成, etc.(Korean Hanja) Pronounced Pron. /il.sʌŋ/ [key·simplify] Meaning & History From Sino-Korean 日 (il) meaning "sun, day" and 成 (seong) meaning "completed, finished, succeeded". Other hanja character combinations are possible. A notable bearer was Kim Il-sung (1912-1994), the first leader of North Korea. Related Names Rootsil + seong Categories celestial, completion, days, history, isograms, kings, Korean, murderers, nature, success, sun, time periods, tyrants