Yeah, I suppose it would literally be "world"...but they certainly knew that the Earth is round. The word for "circle" is "orbis", and the word for "world/planet" is "orbis terrarum" - literally "circle of lands."
Hmm...that's a good question! You can split that up into two different questions for a more clear answer: what languages are closest to Latin in terms of vocabulary, and which languages are closest in terms of grammar.
For the first, that's easily Italian: I know of a joke that Italian is basically "Latin words in the ablative case". But the second...I've heard that, grammatically, Romanian
is the closest to Latin.
French, Spanish, Sardinian, and Portuguese all have aspects of Latin as well.
edited 21st Jul '12 9:35:22 AM by Iulla