Dog

1. A fellow; -- used humorously or contemptuously; as, a sly dog; a lazy dog.
2. An iron for holding wood in a fireplace; a firedog; an andiron.
3. A piece in machinery acting as a catch or clutch; especially, the carrier of a lathe, also, an adjustable stop to change motion, as in a machine tool.
4. To hunt or track like a hound; to follow insidiously or indefatigably; to chase with a dog or dogs; to worry, as if by dogs; to hound with importunity.
5. A quadruped of the genus Canis, esp. the domestic dog (C. familiaris).
6. One of the two constellations, Canis Major and Canis Minor, or the Greater Dog and the Lesser Dog. Canis Major contains the Dog Star (Sirius).
7. An iron with fangs fastening a log in a saw pit, or on the carriage of a sawmill.
8. A grappling iron, with a claw or claws, for fastening into wood or other heavy articles, for the purpose of raising or moving them.
9. A mean, worthless fellow; a wretch.