trainer  
noun uk/ˈtreɪ.nər/ us/ˈtreɪ.nɚ/
  (PERSON)      
 B1 [ C ]教员,教练;培训师;驯兽师 
a person who teaches skills to people or animals and prepares them for a job, activity, or sport
  They showed pictures of the horse and its trainer (= the person who prepared it for its races). 他们展示了这匹马和驯马师的照片。 
 A lot of wealthy people have their own personal trainer (= a person they employ to help them exercise). 许多富人都有自己的私人健身教练。 
 - More examples
 - Her new trainer has promised to make an olympic athlete of her.
 - She hired a trainer to create a personalized exercise schedule to get her into shape.
 - Her trainer is a triple Olympic champion.
 - The horse has had a new trainer for the last six months.
 - He works as a trainer for insurance company staff.
 
  (SHOE)     
A2 [ C usually plural ] UK (UK also training shoe); (US sneaker)运动鞋 
a type of light, comfortable shoe that can be worn for sport
 - More examples
 - Trendy trainers and designer labels have become aspirational status symbols, especially among the young.
 - Please wear trainers in the gym, to avoid scuffing the floor.
 - He's got some wicked trainers.