WordWeb fully covers American, British, Australian, Canadian and Asian English spellings and words. It is updated regularly, and has no annoying adverts.
If a word isn't found the search feature automatically searches other dictionaries and an encyclopedia, and shows you anything it finds. The database indexes over a million different entries. You can also cross-reference to definitions on other sites. And if you don't know a word in a definition, you can click on it to take you to its definition.
Size ("21.3 Mb")