the.com/pet

means A domesticated animal kept for companionship rather than labor or food — and, by extension, anyone or anything treated as a favored, coddled darling.

from Pet shows up in English in the late medieval period, first as a Scottish and northern English word for a pampered or indulged child, especially a spoiled lamb raised by hand rather than its mother. Its roots before that are murky — possibly linked to 'petty' (small, minor) via French petit, though that connection is unproven and often just assumed rather than confirmed. By the 1500s the word had wandered from indulged children to indulged animals, and by extension to the verb 'to pet,' meaning to stroke or indulge fondly. So the creature you now feed kibble and existential dread to was, linguistically, always destined to be spoiled.