knock

1 knock /ˈnɑːk/ verb
knocks; knocked; knocking
1 knock
/ˈnɑːk/
verb
knocks; knocked; knocking
Britannica Dictionary definition of KNOCK
1 
[no object] : to hit something (such as a door) with the knuckles of your hand or with a hard object (such as a knocker) in order to get people's attention — usually + on
— sometimes used figuratively
2 
always followed by an adverb, adjective, or preposition, [+ object] : to hit (something or someone) in a forceful way
3 
always followed by an adverb or preposition : to touch or hit someone or something in a way that is not planned or intended
[no object]
[+ object]
4 
[+ object] : to make (something, such as a hole) by hitting something
5 
[+ object] informal : to criticize (someone or something)
6 
[no object] : to produce a repeated loud noise

heart is knocking

informal
◊ If your heart is knocking it is beating very hard, usually because you are nervous or excited.

knees are knocking

informal
◊ If your knees are knocking they are shaking because you are nervous or afraid.

knock around

[phrasal verb] informal also British knock about
1 
a  knock around/about (a place) or knock around/about : to spend time in (a place) without having a goal or purpose : to wander around (a place)
b  knock around/about with (someone) British : to spend time with (another person)
2 
a  : to be considered or discussed in an informal way over a period of time
b  knock around (something) or knock (something) around : to consider or talk about (ideas, plans, etc.) in an informal way
3 
knock (someone) around/about : to beat or hit (someone) badly or repeatedly — often used figuratively
4 
chiefly British : to be lying somewhere within a general area or place

knock back

informal
1 
knock (something) back or knock back (something) : to drink or swallow (an alcoholic drink) quickly
2 
knock (someone) back : to cost (someone) a lot of money

knock down

[phrasal verb]
1 
knock (someone or something) down or knock down (someone or something)
a  : to cause (someone or something) to fall to the ground
b  British : to hit and injure or kill (a person or animal) with a vehicle
2 
informal
a  knock (something) down or knock down (something) : to reduce or lower (a price, an amount, etc.)
b  knock (someone) down : to cause or persuade (someone) to reduce a price
3 
knock down (an amount of money) US, informal : to receive (an amount of money) as income or salary
4 
knock down (a shot) or knock (a shot) down basketball : to succeed in making (a shot) especially from a long distance
5 
knock (something) down or knock down (something) chiefly US, informal : to say no to (an idea, plan, proposal, etc.) : reject
6 
knock (something) down or knock down (something) US : to take (something) apart

knock heads

US, informal
1 
: to argue or disagree
2 
: to use angry or forceful methods to control or punish people
— often + together

knock in

[phrasal verb]
knock (a run or runner) in or knock in (a run or runner) baseball
: to cause (a run or runner) to score

knock off

[phrasal verb] informal
1 
knock off or knock (something) off or knock off (something) : to stop doing something (such as work)
— often used as a command to tell someone to stop doing something immediately
2 
knock (something) off or knock off (something)
a  : to do or make (something) very quickly
b  : to take (an amount) away from something
c  US : to steal money or things from (a bank or store)
d  chiefly British : to steal (something)
e  US : to make a cheaper copy of (something)
— see also knockoff
3 
knock (someone) off or knock off (someone)
a  : to kill (someone)
b  US : to defeat (someone)

knock on wood

— see 1wood

knock out

[phrasal verb]
1 
knock (someone or something) out or knock out (someone or something)
a  : to make (a person or animal) unconscious
b  boxing : to defeat (an opponent) with a punch that knocks the opponent down for a certain amount of time — see also 1knockout 1
c  : to defeat (an opponent) in a competition so that the opponent cannot continue
d  baseball : to cause (a pitcher) to be removed from the game by getting many hits
2 
knock (something) out or knock out (something)
a  : to cause (something) to stop working
b  : to produce (something) very quickly
3 
knock (yourself) out informal
a  : to make (yourself) very tired by doing work
b  US — used to tell someone to go ahead and do something
4 
knock (someone) out informal : to make a very strong and good impression on (someone)
— see also 1knockout 2

knock over

[phrasal verb]
1 
knock (someone or something) over or knock over (someone or something)
a  : to cause (someone or something) to fall to the ground
b  British : to hit and injure or kill (a person or animal) with a vehicle
2 
knock (someone) over or knock over (someone) informal : to greatly surprise or shock (someone)
3 
knock (something) over or knock over (something) US, informal
a  : to steal money or things from (a bank or store)
b  : to steal (something)

knock (someone) cold

: to cause (someone) to become unconscious

knock (someone) dead

informal
: to make a very strong and good impression on (someone)

knock (someone) for a loop

— see 1loop

knock (someone) for six

— see six

knock someone's head/block off

informal
: to hit someone very hard

knock (someone) sideways

British
: to upset, confuse, or shock (someone) very much

knock some sense into

— see 1sense

knock (something) on the head

British, informal
: to cause the end or failure of (something)

knock spots off

— see 1spot

knock the (living) daylights out of

— see daylight

knock the stuffing out of

— see stuffing

knock together

[phrasal verb]
knock (something) together or knock together (something)
: to make or build (something) in a quick or careless way

knock up

[phrasal verb]
1 
knock (someone) up or knock up (someone) informal
a  chiefly US, impolite : to make (someone) pregnant
b  British : to wake (someone) by knocking on a door
2 
knock (something) up or knock up (something) British : to make or produce (something) quickly

knock your socks off

— see 1sock
2 knock /ˈnɑːk/ noun
plural knocks
2 knock
/ˈnɑːk/
noun
plural knocks
Britannica Dictionary definition of KNOCK
1 
[count]
a  : a hard, sharp hit
b  : the sound made by a hard hit
2 
[count] informal : an experience that makes you less confident or successful for a period of time : a difficult or painful experience
— see also hard knocks (below)
3 
[count] informal : a critical or negative comment — often used in U.S. English in the phrase the knock against
4 
: a loud noise produced by an engine when it is not working properly
[count]
[noncount]

hard knocks

: difficult or painful experiences that people have in their lives or careers