What is phenyle?

"Phenyl" is the name for an organic group in covalent compounds. Formally, a phenyl group results from chemically modifying one of the carbons in a benzene ring to replace the hydrogen originally attached to the reacted carbon by some other group. One way of writing the formula of phenyl is -C6H5, but by itself, this group is not stable at standard temperature and pressure, because it is a free radical and as such very reactive.