Which word is a synonym, or a word that means the same, as pretty?

Which word means the opposite, or is an antonym, to peaceful

Which word is an antonym for splendid?

What would you use a thesaurus for?

Which reference material would I use to find how to spell a word correctly?

If I'm working in a textbook and need to look up what a word means, what is located at the back of the book for me to use?

Which word is a synonym for nasty?