1. past tense of knock; struck or hit something with force
2. past tense of knock; made a sound by hitting a door or surface to get attention
3. past tense of knock; caused something to fall or move by hitting it

Examples

• She knocked on the door three times.
• The ball knocked the vase off the table.
• He knocked his head against the low ceiling.
• The wind knocked down several trees.
• The critics knocked the new movie.
• I knocked loudly but no one answered.
• She accidentally knocked over her coffee cup.