person that you like and know very well
person who is of the same country, group, etc. as oneself; ally
thing that is very helpful or familiar
"he was my best friend at the university"
"he's a good ally in fight"
"I have trouble remembering the names of all my acquaintances"
"we are friends of the family"
"all their supporters came out for the game"
"they are friends of the library"
An intimate and beloved friend of my own.
出自： R. G. Collingwood
A friend in need is a friend indeed.