coach:
(also, less commonly: ‘coacher‘; plural: ‘coaches‘; pronunciation: the first ‘c’ is said with a ‘k’ sound as in “king” — for the right pronunciation of this word, please click here)

a football coach (L) & players
a senior sportsperson who trains junior sports persons for games, competitions, etc.;
a teacher who prepares a student in a particular activity, or for a competitive examination, giving special classes to an individual pupil or a small group of students, and in this context, also a person who trains a singer or actor; a tutor,

an academic coach (L) with her student
The young footballer is looking for a coach who can train him for the coming football season.
In competitive sports, coaches shoulder more responsibility, and so when a cricket team wins a match, its coach gets some of the reward in the form of cash awards and perks, but when the team loses, the coach gets most of the blame and is dismissed!
After retiring from active show business, Julia took up the job as a coach at an acting school, coaching new young students who are training to be real actors and actresses one day.
When Sam and Jim realised that it was difficult for them to prepare for the exams all by themselves, they asked their parents to find some good coaches for them.
