Define is an instrumental electronic track by South Korean producer Zekk (Choi Min-hyuk), originally released as part of Diverse System's Stream Palette album series in 2021. The Stream Palette project operates under a distinctive premise: all tracks are freely licensable for streaming use without individual permission checks, a collaborative initiative that involved game streamer k4sen in its production. The song joined maimai DX on May 13, 2022 as part of the UNiVERSE PLUS update under the GAME & VARIETY category. Beyond the arcade, Define gained wider recognition as the opening theme for VTuber Saikyou Ketteisen ver. APEX LEGENDS Season 2, a prominent VTuber tournament series. Zekk's subsequent Stream Palette contributions would go on to serve as opening themes for later seasons of the same tournament, cementing a recurring association between his music and the event. Zekk had already established himself in the rhythm game scene prior to Define, contributing original compositions to DANCERUSH STARDOM, Arcaea, and WACCA, among others. Define's jacket artwork features the character silky6, using the standing illustration from Stream Palette 2. The song is purely instrumental with no vocal or lyrical content.