dictionary.com is a website plenty of possibilities. You can try different items:
dictionary, thesaurus, reference, translate
and web.
Each page contains different hyperlinks:
Word of the day: Is published a word and the explanations proper of an english
dictionary.
spanish word of the day: Is published a word in Spanish, and it is explained in English.
In the hyperlink ''Fun and games'' you can find
crosswords, help to complete the crosswords and word games.
In the hyperlink ''Features, Premium Membership, Podcast, medical, legal and reverse dictionaries.
In ''Translations'' you can find resources to translate phrases and a multilingual dictionary.
In ''Language Resources'' you can revise your literary stile and grammar.
A very interesting site to improve your English.