Open English Wordnet
Adjectives
(s)casual, insouciant, nonchalantmarked 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”
(s)casual, cursory, passing, perfunctory, superficialhasty 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”, “In his paper, he showed a very superficial understanding of psychoanalytic theory”
(s)casual, occasionaloccurring on a temporary or irregular basis“casual employment”, “a casual correspondence with a former teacher”, “an occasional worker”
(s)free-and-easy, casualnatural and unstudied“using their Christian names in a casual way”, “lectured in a free-and-easy style”
(s)casual, effortlessnot showing effort or strain“a difficult feat performed with casual mastery”, “casual grace”