c.1500, "typical, common;" 1640s, "standing at a right angle," from Late Latin normalis "in conformity with rule, normal," from Latin normalis "made according to a carpenter's square," from norma "rule, pattern," literally "carpenter's square" (see norm). Meaning "conforming to common standards, usual" is from 1828, but probably older than the record [Barnhart].
As a noun meaning "usual state or condition," from 1890. Sense of "normal person or thing" is from 1894. Normal school (1834) is from French école normale (1794), a republican foundation. The city of Normal, Illinois, U.S., was named 1857 for the normal school established there.
normal nor·mal (nôr'məl)
Conforming with, adhering to, or constituting a norm, standard, pattern, level, or type; typical.
Functioning or occurring in a natural way; lacking observable abnormalities or deficiencies.
Occurring naturally and not because of disease, inoculation, or any experimental treatment. Used of immunity.
Of, relating to, or being a solution having one gram equivalent weight of solute per liter of solution.
Of, relating to, or being an aliphatic hydrocarbon having a straight and unbranched chain of carbon atoms.
Of, relating to, or characterized by average intelligence or development.