Achromatic means "without color". An achromatic lens is a lens that is virtually free from prismatic color distortions.
it means...that you mean what you mean:)
1.not nice 2.rude and disrespectful to other people 3.opposite of nice 4.cruel 5.harsh through words or actions
it means average distance which equals the total of each distance divided by how many sets of numbers you previously added by.
mulit means many of something and the word is a prefix