undesigned (adj.)

• automatic
• casual
• ill-advised
• ill-considered
• inadvertent
• involuntary
• reflex
• reflexive
• spontaneous
• unadvised
• unconscious
• unconsidered
• unguarded
• unguided
• unintended
• unintentional
• unplanned
• unpremeditated
• unprompted
• unstudied
• unthinking
• unthought
• unthought-of
• unwilled
• unwitting