Well, you can download the online dictionary from the
www.babylon.com site. It is not free, but it provides a user interface for translations from different languages into different languages. Its Hebrew vocabulary is especially rich since the Babylon company is owned by the Israeli businessmen. But the other glossaries are good as well. It is not an advertisement, I just share my experience of usage of this facility.
You can translate words by either typing them in the window, or by right-clicking (with Alt or Ctrl) the word on the Web page.