unmotivated

1. (of a person or persons) Lacking motivation, without impetus to strive or excel.Examples: "Near-synonym: demotivated"; "an unmotivated student"; "When a typically chatty employee who often participates in meetings and is engaged and enthusiastic suddenly becomes unmotivated and quieter, that person could be at risk for burnout."Antonyms: motivated, remotivated

2. (of an act or behavior) For which there is no motive, or no apparent rational motive.Examples: "Near-synonym: unprovoked"; "an unmotivated murder"; "An inherited etymology should not involve too many unmotivated irrregular sound changes aor ^([sic]) non-trivial semantic shifts."