Definition is the fourth mini album by Japanese visual kei band Diaura, released on 13 February 2019, by NDG.

[5] On October 24, 2018, a single titled "Malice" was released off the album.

[6] A music video was made for the song "Dantōdai kara ai o komete (断頭台から愛を込めて)".

[2] Definition discusses the existence of humanity, what humanity is, and thus was released in two versions, with two different covers: one with the theme "organic" and the other being "mechanic".

The two types begin with two different songs, "ivy" and "Phantom", respectively, which discuss the "illusion of humanity" from different perspectives.