Pet

Pet, a. Petted; indulged; admired; cherished; as, a pet child; a pet lamb; a pet theory.

Some young lady's pet curate.
F. Harrison.

Pet cock. [Perh. for petty cock.] (Mach.) 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, v. t. [imp. & p. p. Petted; p. pr. & vb. n. Petting.] To treat as a pet; to fondle; to indulge; as, she was petted and spoiled.

Pet (?), n. [Formerly peat, perhaps from Ir. peat, akin to Gael. peata.] 1. A cade lamb; a lamb brought up by hand.

2. Any person or animal especially cherished and indulged; a fondling; a darling; often, a favorite child.

The love of cronies, pets, and favorites.
Tatler.

3. [Prob. fr. Pet a fondling, hence, the behavior or humor of a spoiled child.] A slight fit of peevishness or fretfulness. "In a pet she started up." Tennyson.

Pet, v. i. To be a pet. Feltham.