dirt
World is another name for earth. It satarts with a W.
mantle, magma
there is none. maybe on another planet, but not on earth
looser
This Island Earth
Another name for the shaker of the earth is "earthquake."
scree
Try garibaldi!
Atmosphere
intriguing
Their is not another name for HIV that starts with an R. That said, HIV is a type of retrovirus. That is probably the word you are looking for.
Another name for a meteor that is visible from Earth is Meteoroid.