Hypothalamic Amenorrhea. Amenorrhea simply means the absence of menstruation (one or more missed menstrual periods), and it can be caused by a variety of things, including problems with the reproductive organs or hormones.
Normality is an ambiguous measure of the concentration of a solution. It needs a definition of the equivalence factor, which depends on the definition of equivalents. The same solution can possess different normalities for different reactions.
The term Singularity has many definitions. The everyday English definition of Singularity is a noun that designates the quality of being one of a kind, strange, unique, remarkable or unusual. For a more specific definition of Singularity we can search The Wiktionary where we get the following five Singularity definitions: