pet rock in English dictionary pet rock Meanings and definitions of "pet rock" noun A rock one keeps and cares for as if it were a pet, often purchased as a novelty item and treated, with humorous intent, as if it has needs like those of a living animal. more Grammar and declension of pet rock pet rock (plural pet rocks) more Pet Rock Sample sentences with "pet rock" Declension Stem Match words all exact any Try again Available translations Finnish French German Authors