Encyclopaedia or Encyclopedia?
Your choice
Encyclopaedia
Exemple : ‘’The encyclopaedia had information on every topic imaginable.’’
The spelling of the noun "encyclopaedia" varies depending on whether you spell it in the British or American way. The British spelling has a string of silent vowels together towards the end of the word.
Encyclopedia
Exemple : ‘’I used the encyclopedia to research the history of Italy.’’
The American spelling is much closer to the way in which the word is pronounced.