1men·tor 
/ˈmɛnˌtoɚ/ noun
plural men·tors /ˈmɛnˌtoɚ/ noun [count] : someone who teaches or gives help and advice to a less experienced and often younger person
▪ After college, her professor became her close friend and mentor. ▪ He needed a mentor to teach him about the world of politics. ▪ We volunteer as mentors to/of disadvantaged children. ▪ young boys in need of mentors
▪ After college, her professor became her close friend and mentor. ▪ He needed a mentor to teach him about the world of politics. ▪ We volunteer as mentors to/of disadvantaged children. ▪ young boys in need of mentors
