INSOUCIANT
casual, insouciant, nonchalant
(adjective) 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”
Source: WordNet® 3.1
Etymology
Adjective
insouciant (comparative more insouciant, superlative most insouciant)
Casually unconcerned; carefree, indifferent, nonchalant.
Anagrams
• incautions
Source: Wiktionary
In`sou`ciant", a. Etym: [F.]
Definition: Careless; heedless; indifferent; unconcerned. J. S. Mill.
Source: Webster’s Unabridged Dictionary 1913 Edition