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.
Noun. 1. reactant-a chemical substance that is present at the start of a chemical reaction. chemical, chemical substance-material produced by or used in a reaction involving changes in atoms or molecules.1  Facebook. 2  Twitter.oun. 1. reactant-a chemical substance that is present at the start of a chemical reaction. chemical, chemical substance-material produced by or used in a reaction involving changes in atoms or molecules.