" unconcerned "

1: having or showing freedom from worries or troubles;

  * e.g., " ... playful and unconcerned despite his medical emergency "

•  Synonyms : 

•  blithe,

•  carefree,

•  debonair,

•  devil-may-care,

•  gay,

•  happy-go-lucky,

•  insouciant,

•  lighthearted,

•  lightsome,

•  slaphappy

•  Antonyms : 

•  careworn

2: having or showing a lack of interest or concern;

  * e.g., " ... a featherbrain completely unconcerned about the important issues of the day "

•  Synonyms : 

•  apathetic,

•  casual,

•  complacent,

•  disinterested,

•  incurious,

•  indifferent,

•  insensible,

•  insouciant,

•  nonchalant,

•  perfunctory,

•  pococurante,

•  uncurious,

•  uninterested

•  Antonyms : 

•  concerned,

•  interested