narcotic
numbing drug
Today this word meansA drug that dulls the senses and brings on sleep.
From Greek narkē — numbness, insensibility.
One view derives the flower name narkissos, narcissus, from the same word — because its scent makes people drowsy and dazed.
Worth noting
If so, the boy was named after the flower, not the other way around. Which came first, though, remains unsettled.