haphazard

Synonyms: accidental aimless all over the map any old way any which way arbitrary careless casual chance designless desultory devilmay-care disorderly disorganized erratic fluke helter-skelter hit-or-miss incidental indiscriminate irregular loose offhand purposeless random reckless slapdash slipshod spontaneous sudden unconcerned unconscious unconsidered uncoordinated unexpected unmethodical unorganized unpremeditated unsystematic unthinking willy-nilly

Antonyms: careful designed intentional methodical organized planned straight systematic thought-out