ETYM Latin normalis, from norma rule, pattern, carpenter's square; prob. akin to noscere to know; cf. Greek nossos well known, also, carpenter's square: cf. French normal. Related to Known, Abnormal, Enormous.
1. Conforming with or constituting a norm or standard or level or type or social norm; not abnormal.
2. In accordance with scientific laws.
3. (Psychology) Being approximately average or within certain limits in e.g. intelligence and development.
4. (Geometry) Forming a right angle.

1. A normal line; the portion of a normal line to a plane curve between the curve and the x-axis
2. One that is normal
3. A form or state regarded as the norm; standard