Now you can Translate Bangla (Bengali) with Google Translate. Oh, I was wandering about that and now it is appear! See the image below-
Now Google offer the Alpha edition and hope they will offer the Beta edition. I wrote on Google Translator as "Hi! How are you? " and following has come "হাই! কেমন আছ তুমি?". There are some problem on the English to Bengali translation or Bengali to English translation as its still under development. I mean the Bangali to English or English to Bangla is not yet completed. But as Dictionary You may use Google Translator Because it is almost totally ready to translate single word. So what are you waiting for? Go for Translate English to Bangla with Google Translate and check it out at Google Translate.