Although, there is no obvious English cognate, amargo is the Spanish word for bitter. Bittersweet, for example, is amargodulce: literally, bitter-sweet.
Interestingly, though, the very common Spanish word for “yellow,” amarillo, comes from this same root for bitter. It literally means “a bit of bitterness,” from the Latin amarus for “bitter” with the -illo diminuitive ending.
Yellow — the color of melancholy, of puke, of snot — is really the color of just a hint of bitterness.
