a quadruped of the genus canis, esp. the domestic dog (c. familiaris).-a mean, worthless fellow; a wretch.-a fellow; -- used humorously or contemptuously; as, a sly dog; a lazy dog.-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).-an iron for holding wood in a fireplace; a firedog; an andiron.-a grappling iron, with a claw or claws, for fastening into wood or other heavy articles, for the purpose of raising or moving them.-an iron with fangs fastening a log in a saw pit, or on the carriage of a sawmill.-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.-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.