Merriam-Webster's Collegiate® Dictionary, 11th Edition
DOG
I. noun
Usage: often attributive
Etymology: Middle English, from Old English docga Date: before 12th century
1. canid , a male dog,
2. a worthless or contemptible person, fellow , chap ,
3. any of various usually simple mechanical devices for holding, gripping, or fastening that consist of a spike, bar, or hook, andiron , uncharacteristic or affected stylishness or dignity , either of the constellations Canis Major or Canis Minor, feet , ruin , one inferior of its kind , an investment not worth its price, an undesirable piece of merchandise, an unattractive person, hot dog 1, doglike adjective
II. adjective
Date: 14th century
canine , spurious ,
III. transitive verb (dogged; dogging)
Date: 1519
1. to hunt, track, or follow like a hound , to worry as if by pursuit with dogs ; plague , to bother or pester persistently , to fasten with a dog,
IV. adverb
Date: 1526
extremely , utterly