means An aromatic plant substance — like pepper, cinnamon, or clove — used to flavor food, or by extension anything that adds excitement or zest.

from From Old French 'espice,' worn down from Latin 'species,' which meant 'kind' or 'sort' — the same word that gives us 'species' and 'special.' In late Latin and medieval trade, 'species' came to mean 'goods,' especially the precious aromatic wares sold by weight, until the word narrowed to mean the prized seeds, barks, and roots themselves. So a spice is, quite literally, a 'particular kind of thing' — the merchant's catch-all for the small valuable items worth their weight in gold.