Synonyms and related words :
airy, blithe, breezy, buoyant, carefree, cheery, chirk, chirpy, chirrupy, clear, cloudless, corky, debonair, diaphanous, free and easy, insouciant, jaunty, light, lighthearted, lightish, lucent, lucid, luculent, pellucid, perky, relucent, resilient, serene, sunny, translucent, translucid, transparent, unclouded, unobscured