I look for a piece of wood to knock on every time I tell somebody that we seem to be doing okay right now.
The Daily Mail has a long tradition building 'em up to knock 'em down, and it seems even poor Pippa Middleton isn't immune.
A knock came at the door and this time her dread became real in the persons of two government officials.
The first in the room, to knock down the door, to break down the barriers, to pave the road that we all walk on.
A canvasser will knock on their door and ask voters to sign the card.
At last I managed to knock the wall, and got Jem to come to the door.
There was a knock on the door of the box, and an attendant put in his head.
But when all that is finished, it will take you seven or eight solid days to pick it to pieces again, and knock it straight.
They waited for some time and then there was a knock at the outer door.
They produce, in leaping, one sharp rap, and often knock many raps when they are prevented from projecting themselves.
Old English cnocian (West Saxon cnucian), "to pound, beat; knock (on a door)," likely of imitative origin. Meaning "deprecate, put down" is from 1892. Related: Knocked; knocking. Knock-kneed first attested 1774. Knock-down, drag-out is from 1827. Command knock it off "stop it" is first recorded 1880, perhaps from auctioneer's term for "dispose of quickly:"
At the commencement of the sales, he gave every one that wanted to purchase a paper containing a description of the lands that were to be sold; and, as the sales were cried, he called over the numbers and described the land; and when it got up to one dollar and a quarter an acre, if no body bid, after it was cried two or three times, he would say, knock it off, knock it off. [U.S. Senate record, 1834]
mid-14c., from knock (v.). As an engine noise, from 1899.
: It wasn't a disinterested comment—it was a knock/ The knock on Fernandez is he can't field