Word Meaning: Radical Expressions and Square Root.

The word "radical" comes from the Latin word "radix", that means "root",
from what we get not only the word "radical", but also "radish"! The
other use of "radical" means "by the roots" or "from the roots", such as a "radical" change in a person. A political"radical" is someone who wants radical change by radical means, like an extremist. Another word from the same source is "eradicate" originally, to "root out" or "pull out by the roots". And a square root is called a root in the first place because a root is the source of something. If you square a number, the number it came from is the root, as if the square grew from it.