New American Oxford Dictionary
slaphappy
slap hap py |ˈslapˌhapē ˈslæpˌhæpi | ▶adjective informal 1 casual or flippant in a cheerful and often irresponsible way: he possessed slaphappy courage. • (of an action or operation ) unmethodical; poorly thought out: slaphappy surveying methods. 2 dazed or stupefied from happiness or relief: she's a bit slaphappy after such a narrow escape.
American Oxford Thesaurus
slaphappy
slaphappy adverb informal 1 his slaphappy friend: happy-go-lucky, devil-may-care, carefree, easygoing, nonchalant, insouciant, blithe, airy, casual. 2 slaphappy work. See slapdash. 3 she's a bit slaphappy after such a narrow escape: dazed, stupefied, punch-drunk.