According to the dictionary a friend is a person whom one knows, likes, and trusts or person whom one knows; an acquaintance, a person with whom one is allied in a struggle or cause; a comrade. Another has the definition as a person whom one knows and with whom one has a bond of mutual affection, typically exclusive of sexual or family relations. (kind of disagree with that last part since my best friend as a child was my cousin, he got me into and of of trouble and we had a bond).
A loyal friend is a powerful defence: whoever finds one has indeed found a treasure. Sir 6:14. I have that in a guy, he's a guy I can count on to pray for me and give me good advice.
A loyal friend is the elixir of life, and those who fear the Lord will find one. Sir 6:16. I also have this in a few guys, they have me laughing all the time. They bring out the competitive side in me and take me back to my childhood.
Check out Jen to see what everyone else had to say.