Read, read, read! Everything that you can get your hands on will help you to increase your vocabulary. If you come across a word you don't know, try to guess its meaning from the context. If that fails, then look up the word in a dictionary or on the Internet.
Step2
Talk to people with large vocabularies. This may include teachers, professors or other smart people. You can also watch many college lectures on the education channel offered by many satellite and cable providers.
Step3
When you heard or see an especially unusual word, write it down. Not only will writing the word help you to remember it and its meaning, but after a time, you will have your own specially tailored dictionary that caters to your tastes.
Tips & Warnings
Don't forget that language is everywhere. Be aware. You might even learn a new word while watching the evening news.
If you use the Internet to define words, make sure that the definition is agreed upon by at least three different sources. Remember, not everything on the Internet is true.
Enthusiast 
