knock
英 [nɒk]
美[nɑk]
	    - vi. 敲;打;敲击
 - vt. 敲;打;敲击;批评
 - n. 敲;敲打;爆震声
 
英英释意
- 1. the sound of knocking (as on a door or in an engine or bearing);
 - "the knocking grew louder"
 
- 2. negative criticism
 
- 3. a vigorous blow;
 - "the sudden knock floored him"
 - "he took a bash right in his face"
 - "he got a bang on the head"
 
- 4. a bad experience;
 - "the school of hard knocks"
 
- 5. the act of hitting vigorously;
 - "he gave the table a whack"