casual

hasty and without attention to detail; not thorough

“a casual (or cursory) inspection failed to reveal the house's structural flaws”

characterized by a feeling of irresponsibility

“a broken back is nothing to be casual about; it is no fooling matter”

occurring on a temporary or irregular basis

“casual employment”

occurring or appearing or singled out by chance

“seek help from casual passers-by”

marked by blithe unconcern

“an ability to interest casual students”

natural and unstudied

“using their Christian names in a casual way”

not showing effort or strain

“a difficult feat performed with casual mastery”

appropriate for ordinary or routine occasions

“casual clothes”

without or seeming to be without plan or method; offhand

“a casual remark”