the.com/poppy seed

means The tiny oil-rich seed of the opium poppy, used whole for baking and crunch or pressed for oil, which contains trace amounts of morphine and codeine left over from the plant's sap.

from The word 'poppy' traces back to Old English 'popæg', itself borrowed from Latin 'papaver' — the plant's own name since antiquity, of uncertain deeper origin. 'Seed' is just the plain old Germanic word for, well, seed. The seeds themselves are harvested from the same species, Papaver somniferum ('sleep-bringing poppy'), that yields opium — but the seeds form after the plant's narcotic sap has already been scored and drained, so they're botanically innocent even as they carry faint chemical residue from their notorious parent.