Definitions for slaphappyˈslæpˌhæp i
Random House Webster's College Dictionary
slap•hap•pyˈslæpˌhæp i(adj.)-pi•er, -pi•est.
agreeably giddy or foolish.
carefree, devil-may-care, freewheeling, happy-go-lucky, harum-scarum, slaphappy(adj)
"carefree with his money"; "freewheeling urban youths"; "had a harum-scarum youth"
punch-drunk, silly, slaphappy(adj)
dazed from or as if from repeated blows
"knocked silly by the impact"; "slaphappy with exhaustion"
Incoherent from being struck, punch drunk.