crocodile  
noun [ C ] uk/ˈkrɒk.ə.daɪl/ us/ˈkrɑː.kə.daɪl/  crocodiles or crocodile
  (ANIMAL)      
 B2 (informal croc, uk/krɒk/ us/krɑːk/)鳄鱼 
a large reptile with a hard skin that lives in and near rivers and lakes in hot, wet parts of the world. It is like an alligator, but it usually has a longer and narrower nose
  a crocodile-infested swamp 鳄鱼出没的沼泽 
 - More examples
- Humans, dogs, elephants and dolphins are all mammals, but birds, fish and crocodiles are not.
- On average, two crocodiles a year end up as road kill on Florida's Highway 1.
- He lost an arm to a crocodile.
  (LINE)     
 UK informal两人一排成纵队行走的人(尤指儿童) 
a line of people, especially children, who are walking in pairs