dog

1 dog /ˈdɑːg/ noun
plural dogs
1 dog
/ˈdɑːg/
noun
plural dogs
Britannica Dictionary definition of DOG
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.
— often used before another noun
b  : a male dog
2 
[count] informal
a  : a person who is regarded as lucky, unlucky, etc. — see also top dog
b  : a person who is lazy or who is not liked
c  offensive : an unattractive girl or woman
3 
[count] US, informal : something that is poor in quality
4 
[count] US, informal : hot dog — see also chili dog, corn dog
5 
dogs [plural] US, informal + old-fashioned : feet

a dog's breakfast

British, informal
: something that is messy or poorly done

a dog's life

: a difficult, boring, and unhappy life

(as) sick as a dog

informal

dog and pony show

US, usually disapproving
: a very fancy and elaborate event that is done to sell something, to impress people, etc.

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

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

put on the dog

US, informal + old-fashioned
: to pretend that you are very stylish or rich

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
2 dog /ˈdɑːg/ verb
dogs; dogged; dogging
2 dog
/ˈdɑːg/
verb
dogs; dogged; dogging
Britannica Dictionary definition of DOG
[+ object]
1 
: to follow (someone) very closely
2 
: to ask (someone) about something or for something constantly or frequently
3 
: to cause problems for (someone) for a long time — often used as (be) dogged