Knock

How to spell knock

5 letters · 1 syllable

How to pronounce knock

What does knock mean?

1. verbTo strike a surface with a sharp blow, especially to rap on a door to get attention.
2. nounA sharp blow or the sound it makes, often a tap on a door.

Knock in a sentence

• verb

  Please knock before you enter the office.

• noun

  A sudden knock at the door startled the whole family.

• verb

  The courier had to knock twice before anyone answered.

• noun

  The old car developed a worrying knock in the engine.

Where does knock come from?

Language of origin: Germanic

Knock comes from the Old English verb cnocian, meaning to strike or pound, and it is an imitative or echoic word: the sound of the spoken word was meant to suggest the sound of one hard object striking another. Closely related forms appear in Old Norse knoka and in several other Germanic tongues, all carrying the same sense of a sharp blow. The silent letter k at the start is the genuine spelling trap, since in Old and Middle English the k was actually pronounced, giving a sound like 'k-nock'; English speakers stopped pronouncing the initial k in clusters such as kn during the seventeenth century, but the spelling never caught up. This leaves modern writers with a written k that the ear gives no clue about, the same quiet ancestor that haunts knee, knife, and knot. The meaning has stayed remarkably stable for over a thousand years, broadening only gently to cover rapping on a door, criticising someone, or the mechanical knocking of an engine.

How the word is built

• knock (from Old English cnocian, an imitative word for striking)