An immensely useful URL : One Look - a Search Engine of Dictionaries. Find out the definitions of a word given in all major on-line dictionaries. Invaluable if you want to find out how English As She Is Spoke differs from country to country.
As an exercise for non-Australian readers, try using it to have a look at what the (Australian) Macquarie Dictionary has to say about the word "root". For Australian readers, use it to find out what the word means in the rest of the world.