A 'true friend' is the opposite of a 'fair-weather friend'. A fair-weather friend only hangs around for the fun times : if you you become sick, poor or lonely, a fair-weather friend will abandon you. By contrast, a 'true friend' is a friend for life. If you're ill, if you're in trouble, if times are bad, a true friend will always be there for you. A true friend will never betray you or let you down, and will support you and defend you no matter what.

"a true friend" > a friend who has proven his friendship to you by being your friend in your good or bad times .His friendship with you is real unlike others who may not be dependable or those who are just friends in name , but dissappear when you need them

Kenny's right. A true friend is a friend in our good or bad times, a friend you can trust everytime.