- approximately average in any psychological trait, as intelligence, personality, or emotional adjustment.
- free from any mental disorder; sane.
- free from any infection or other form of disease or malformation, or from experimental therapy or manipulation.
- of natural occurrence.
- being at right angles, as a line; perpendicular.
- of the nature of or pertaining to a mathematical normal.
- (of an orthogonal system of real functions) defined so that the integral of the square of the absolute value of any function is 1.
- (of a topological space) having the property that corresponding to every pair of disjoint closed sets are two disjoint open sets, each containing one of the closed sets.
- (of a subgroup) having the property that the same set of elements results when all the elements of the subgroup are operated on consistently on the left and consistently on the right by any element of the group; invariant.
- (of a solution) containing one equivalent weight of the constituent in question in one liter of solution.
- pertaining to an aliphatic hydrocarbon having a straight unbranched carbon chain, each carbon atom of which is joined to no more than two other carbon atoms.
- of or relating to a neutral salt in which any replaceable hydroxyl groups or hydrogen atoms have been replaced by other groups or atoms, as sodium sulfate, Na2SO4.
- a perpendicular line or plane, especially one perpendicular to a tangent line of a curve, or a tangent plane of a surface, at the point of contact.
- the portion of this perpendicular line included between its point of contact with the curve and the x-axis.
Origin of normal
- being within certain limits of intelligence, educational success or ability, etc
- conforming to the conventions of one's group
Word Origin for normal
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.