Wiktionary
a. Not methodical.
WordNet
adj. not efficient or methodical; "the project failed through unmethodical planning"
Usage examples of "unmethodical".
The soreness of that disappointment was intensified when they saw this Western man in the White House, with so much of rustic manner and speech as still clung to him, meeting his fellow-citizens, high and low, on a footing of equality, with the simplicity of his good nature unburdened by any conventional dignity of deportment, and dealing with the great business of state in an easy-going, unmethodical, and apparently somewhat irreverent way.
Chelsea philosopher would probably be a less severe burden to a woman of housewifely instincts than the weak, unmethodical, irresolute, shiftless being that Coleridge had by this time become.
She had been unmethodical, all the evening, breaking off in the middle of a job to start another.
If the woman had been untidy and unmethodical, she had at least had a streak of caution.
Careless and unmethodical as his father was about other things, he wrote every Sunday.