Webster's Revised Unabridged Dictionary · 1913

pet

pet (pet) , noun

[Formerly peat, perhaps from Ir. peat, akin to Gael. peata.]

1.
A cade lamb; a lamb brought up by hand.
2.
Any person especially cherished and indulged; a fondling; a darling; often, a favorite child; as, a teacher's pet.
The love of cronies, pets, and favorites. — Tatler
3.
A slight fit of peevishness or fretfulness.
In a pet she started up. — Tennyson
4.
Any animal kept as a companion, usually in or around one's home, typically domesticated and cared for attentively and often affectionately. Distinguished from animals raised for food or to perform useful tasks, as a draft animal or a farm animal.

pet , adjective

Petted; indulged; favorite; admired; cherished; as, a pet child; a pet lamb; a pet theory; a pet animal.
Some young lady's pet curate. — F. Harrison
Collocations (1)
Pet cock (Machinery) , A little faucet in a water pipe or pump, to let air out, or at the end of a steam cylinder, to drain it.

Pet , transitive verb

To treat as a pet; to fondle; to indulge; as, she was petted and spoiled.

Pet , intransitive verb

To be a pet. — Feltham