Something that never changes; is always there: a pillar, the stars, a person. When people lose a constant in their worlds', it may destabalize them and their worlds'. This may cause any of the following: fear of abandonment, withdrawl, giving up, (major) depression, and more. A constant may also be a type of data structure in a programming language (usually: "const"). "const" is used in physics notation as well, ex.: E=Const means the energy in said system doesn't chan