(n.) Extra hazard; chance; accident; random.

accidental accidentally ad-lib aimless aimlessly amorphous any which way anyhow anywise around at random botched bungling capricious careless carelessly casual casually caught napping caught off balance caught short causeless chance-medley clumsy deficient designless desultory disarticulated discontinuous disjunct disordered dispersed disproportionate driftless dysteleological erratic extemporaneous extemporized fitful formless frivolous gratuitous half-assed haphazardly hasty helter-skelter hit-and-miss hit-or-miss immethodical impromptu improvised inchoate incoherent indiscriminate inexplicable irregular makeshift meaningless messy mindless misshapen nonsymmetrical nonsystematic nonuniform orderless planless potluck precipitate promiscuous promiscuously purposeless random random shot randomly rough-and-ready senseless shapeless slipshod slipshoddy sloppy slovenly sluttish snap spasmodic sporadic stochastic straggling straggly systemless taken aback taken by surprise taken unawares tripped up unaccountable unarranged unbegun unclassified unconcocted unconsidered uncontrived undeliberated undevised undirected ungraded unhatched unjoined unmade unmanufactured unmethodical unmotivated unordered unorganized unplanned unpremeditated unprepared unprimed unready unsorted unstudied unsymmetrical unsystematic untidy ununiform vague wandering