When I moved from Belgium to Estonia at the age of 30, one of my biggest worries was: will I lose my friends?
Here is how I currently define “friend”:
Somebody to whom you do not refuse your help even when it requires a reasonable effort
Of course “reasonable” still remains subjective.
This definition is special in that it turns the classical definition upside-down: the condition lies within me, not within the other person.
I don’t need to ask “Are you my friend?”, I can say “ I consider you as my friend and I hope that you also consider me as your friend.”