Hydrocephalus is a buildup of fluid inside the skull that leads to brain swelling. Hydrocephalus means water on the brain.
locant. (chemistry). The portion of a chemical name, usually a number or a letter, that designates the position of an atom or group of atoms in a formula unit. 1  Facebook. 2  Twitter.
The locant is incorporated into the name of the molecule to remove ambiguity. Thus the molecule is named either pentan-2-one or pentan-3-one, depending on the position of the oxygen atom.