1dog 
/ˈdɑ:g/ noun
plural dogs /ˈdɑ:g/ noun 1 [count] a : a type of animal that is often kept as a pet or trained to work for people by guarding buildings, hunting, etc.
▪ That dog barks all day long. ▪ children playing with the family dog ▪ a guard dog ▪ a hunting dog ▪ wild dogs such as the Australian dingo — often used before another noun ▪ a dog collar ▪ dog food/shows ▪ I'm not really a dog person. [=I don't particularly like dogs]
b : a male dog 2 [count] informal a : a person who is regarded as lucky, unlucky, etc.
▪ You lucky dog! — see also top dog
b : a person who is lazy or who is not liked
▪ He's a lazy dog. ▪ He's a worthless dog. [=bum]
c offensive : an unattractive girl or woman
▪ They say she's a real dog. 3 [count] US, informal : something that is poor in quality
▪ Her latest book turned out to be a real dog. ▪ That was a dog of a movie. 4 [count] US, informal : hot dog
▪ Would you like another dog? — see also chili dog, corn dog 5 dogs [plural] US, informal + old-fashioned : feet
▪ My dogs were tired from standing all day.
▪ That dog barks all day long. ▪ children playing with the family dog ▪ a guard dog ▪ a hunting dog ▪ wild dogs such as the Australian dingo — often used before another noun ▪ a dog collar ▪ dog food/shows ▪ I'm not really a dog person. [=I don't particularly like dogs]
b : a male dog
▪ You lucky dog! — see also top dog
b : a person who is lazy or who is not liked
▪ He's a lazy dog. ▪ He's a worthless dog. [=bum]
c offensive : an unattractive girl or woman
▪ They say she's a real dog.
▪ Her latest book turned out to be a real dog. ▪ That was a dog of a movie.
▪ Would you like another dog? — see also chili dog, corn dog
▪ My dogs were tired from standing all day.
a dog's breakfast
Brit, informal : something that is messy or poorly done
▪ It was a dog's breakfast of a match, and our coach was understandably upset.
▪ It was a dog's breakfast of a match, and our coach was understandably upset.
a dog's life
: a difficult, boring, and unhappy life
▪ Everyone knows it's a dog's life in this business.
▪ Everyone knows it's a dog's life in this business.
(as) sick as a dog
informal : very sick
▪ I'm sick as a dog.
▪ I'm sick as a dog.
dog and pony show
US, usually disapproving : a very fancy and elaborate event that is done to sell something, to impress people, etc.
▪ The sales presentation was a real dog and pony show.
▪ The sales presentation was a real dog and pony show.
every dog has his/its day
informal — used to say that every person has a successful moment in life
go to the dogs
informal : to become ruined : to change to a much worse condition
▪ Our favorite restaurant has gone to the dogs lately. ▪ The economy is going to the dogs.
▪ Our favorite restaurant has gone to the dogs lately. ▪ The economy is going to the dogs.
hair of the dog (that bit you) — see hair
in a dog's age — see 1age
let sleeping dogs lie
: to ignore a problem because trying to deal with it could cause an even more difficult situation
▪ I thought about bringing up my concerns but decided instead to let sleeping dogs lie.
▪ I thought about bringing up my concerns but decided instead to let sleeping dogs lie.
put on the dog
US, informal + old-fashioned : to pretend that you are very stylish or rich
▪ They really put on the dog for their daughter's wedding.
▪ They really put on the dog for their daughter's wedding.
rain cats and dogs — see 2rain
the tail wagging the dog — see 1tail
you can't teach an old dog new tricks
— used to say that a person who is old or is used to doing things in a certain way cannot learn or does not want to learn a new way ▪ I tried to get my mother to start using a computer, but she says you can't teach an old dog new tricks.
