blither

(verb) to talk foolishly. Synonyms: babble, blather, smatter, blether. Examples: "The two women babbled and crooned at the baby."

(adj) lacking or showing a lack of due concern. Synonyms: blithe. Examples: "Spoke with blithe ignorance of the true situation."

(adj) carefree and happy and lighthearted. Synonyms: blithe, blithesome, lighthearted, lightsome, light-hearted. Examples: "Was loved for her blithe spirit." "A merry blithesome nature." "Her lighthearted nature." "Trilling songs with a lightsome heart."