This new section is an attempt to assist students to access exact definitions of words they simply don't know. If you have any really good dictionary sites you would like to share with all of us, I would be delighted to publish your findings. If you do write your homework in Microsoft Word, you do have a lot of support via its dictionaries, spell check, thesaurus etc. Let's start with English-English dictionaries. The two chosen ones are both are large: the second being a US English dictionary.
There is a chemistry dictionary which I would also like you to check out. It seems quite good on the surface. Many, many very useful words are included:
The following foreign language dictionaries are the best I have found to date. Other options may well exist.
This first option has been supplied by my Year 10 students. It is apparently an excellent dictionary: Naver. Z-Korean is another reasonable option.
Nciku.com is an excellent dictionary for our Chinese students. I love it.
There is also: 
Click on the 中文 icon above to activate the weblink.
This Japanese-English-Japanese dictionary is one supplied by my Year 10 students. It has science words in it and should be very good indeed.
Again, just click on the icon above to open the weblink.
For our African, European and North or South American students, the following dictionaries are reasonably good. Sadly, I can't make available my own computer's dictionaries. The Aurélio dictionary is considered the best in the Portuguese language. A popular foreign dictionary is the Ectaco dictionary.
The Real Academia Española dictionary should be the only dictionary for a native Spanish speaker. The link below is a Spanish dictionary that is a stand-in at present.
Spanish-English-Spanish dictionary
I haven't asked many students their options yet, but I will add other dictionaries in due course. Let's hope you always bring your translator to class too.
This Larousse English-French-English dictionary was my first choice when I was at school. I didn't become fluent in French. Oh, well. This other choice below may also be quite reasonable:
