roar/ rɔːr /

1.noun [c] [of animal] 
吼叫声

2.noun [of crowd] 
喧哗

3.noun [of traffic] [ storm] 
喧闹声

4.vi.[animal+] 
吼叫

5.vi.[person] [ crowd+] 
大喊大叫

6.vi.[engine] [ wind etc+] 
咆哮

to roar with laughter
哈哈大笑
roar of laughter
大笑声