green, aromatic, olive oil-based pasta sauce, a Genoese specialty, 1937, from Italian pesto, contracted form of pestato, past participle of pestare "to pound, to crush," in reference to the crushed herbs and garlic in it, from Latin root of pestle.
pestiferous
pestilence
pestilent
pestilential
pestle
pesto
*pet-
pet
pet peeve
PETA
petal