adjectives
marked by blithe unconcern
"an ability to interest casual students"; "showed a casual disregard for cold weather"; "an utterly insouciant financial policy"; "an elegantly insouciant manner"; "drove his car with nonchalant abandon"; "was polite in a teasing nonchalant manner"
without or seeming to be without plan or method; offhand
"a casual remark"; "information collected by casual methods and in their spare time"
is similar to
without apparent forethought or prompting or planning
"an unplanned economy"; "accepts an unplanned order"; "an unplanned pregnancy"; "unplanned remarks"
appropriate for ordinary or routine occasions
"casual clothes"; "everyday clothes"
occurring or appearing or singled out by chance
"seek help from casual passers-by"; "a casual meeting"; "a chance occurrence"
hasty and without attention to detail; not thorough
"a casual (or cursory) inspection failed to reveal the house's structural flaws"; "a passing glance"; "perfunctory courtesy"
occurring from time to time
"casual employment"; "a casual correspondence with a former teacher"; "an occasional worker"
characterized by a feeling of irresponsibility
"a broken back is nothing to be casual about; it is no fooling matter"
natural and unstudied
"using their Christian names in a casual way"; "lectured in a free-and-easy style"
not showing effort or strain
"a difficult feat performed with casual mastery"; "careless grace"