(economics) a good for which demand increases when income increases and falls when income decreases but price remains constant, i.e. with a positive income elasticity of demand.

The study of the microscopic structure of living tissue (histology) that is in good health (as opposed to pathological histology which studies that of diseased tissue).

plural of normal pause

(statistics) Any of a family of continuous probability distributions such that the probability density function is the Gaussian function

(group theory) A subgroup H of a group G that is invariant under conjugation; that is, for all elements h of H and for all elements g in G, the element ghg⁻¹ is in H.

Any force acting normal, to a surface, or perpendicular to the tangent plane.

(sports) The standard period of play, contrasted with any additional periods such as injury time, extra time or penalty shootout.

(for an m-step process) the mᵗʰ root of the rolled throughput yield

(differential geometry) A unit vector at any given point P of a surface M which is perpendicular to the tangent plane T_P(M) of M at P. For a surface with parametrization ⃑x(u,v), it is given by

(animation) The four frames of silence between each line of dialog. The name refers to what would be normal pausing between words in the cadence of someone's typical speech pattern.