The most common Korean word for “joyful” is 즐겁다 (jeulgeopda). There is one more word with a similar meaning — compare them below. 「joyful」는 한국어로 즐겁다.
to be joyful; to be pleasant
TOPIK 2 · adjective
Words and levels: TOPIK I essentials (National Institute of Korean Language standard curriculum, KOGL Type 1) · examples: Cheesepotato