Here are a few ;)
Old-Timer: This means first visited more than 180 days ago (silver)
Avid reader: Means you read a Total of 50 questions (silver)
Nice answer: Means your answer received 2+ up votes
Notable question: It means your question got 50 views
Gifted: means one of your answers were selected having the best answer
Grateful: Means you selected one answer as the best
That's just a phew of the meanings comment below if you have any questions and btw you can just roll over your Rank or what ever you got like wise.....good reader.. and it will tell you