• Normal


    • UK IPA: /nɔː(ɹ).məl/
    • Rhymes: -ɔː(r)məl


    From Latin normālis.

    Full definition of normal



    1. According to norms or rules.
      Organize the data into third normal form.
    2. Usual; ordinary.
      • 1963, Margery Allingham, The China Governess Chapter 2, Now that she had rested and had fed from the luncheon tray Mrs. Broome had just removed, she had reverted to her normal gaiety.  She looked cool in a grey tailored cotton dress with a terracotta scarf and shoes and her hair a black silk helmet.
    3. Felicia baked the bread the normal way.
    4. Healthy; not sick or ill.
      John is feeling normal again.
    5. Pertaining to a school to teach teachers how to teach.
      My grandmother attended Mankato State Normal School.
    6. (chemistry) Of, relating to, or being a solution containing one equivalent weight of solute per litre of solution.
    7. (organic chemistry) Describing a straight chain isomer of an aliphatic hydrocarbon, or an aliphatic compound in which a substituent is in the 1- position of such a hydrocarbon.
    8. (physics) (Of a mode in an oscillating system) In which all parts of an object vibrate at the same frequency; See normal mode.
    9. (geometry) Perpendicular to a tangent line or derivative of a surface in Euclidean space.
      • The interior normal vector of a ideal perfect sphere will always point toward the center, and the exterior normal vector directly away, and both will always be co-linear with the ray whose' tip ends at the point of intersection, which is the intersection of all three sets of points.
    10. (algebra) (Of a subgroup) whose cosets form a group.
    11. (algebra) (Of a field extension of a field K) which is the splitting field of a family of polynomials in K.
    12. (probability theory, statistics) (Of a distribution) which has a very specific bell curve shape.
    13. (complex analysis) (Of a family of continuous functions) which is pre-compact.
    14. (set theory) (Of a function from the ordinals to the ordinals) which is strictly monotonically increasing and continuous with respect to the order topology.
    15. (linear algebra) (Of a matrix) which commutes with its conjugate transpose.
    16. (functional analysis) (Of a Hilbert space operator) which commutes with its adjoint.
    17. (category theory) (Of an epimorphism) which is the cokernel of some morphism.
    18. (category theory) (Of a monomorphism) which is the kernel of some morphism.
    19. (category theory) (Of a morphism) which is a normal epimorphism or a normal monomorphism.
    20. (category theory) (Of a category) in which every monomorphism is normal.
    21. (Of a real number) whose digits, in any base representation, enjoy a uniform distribution.
    22. (topology) (Of a topology) in which disjoint closed sets can be separated by disjoint neighborhoods.
    23. (rail transport, Of points) in the default position, set for the most frequently used route.



    Related terms

    Usage notes

    Warning: normal, when used to describe a majority group of people, can be considered offensive to those who don't consider membership of their own minority to be unusual. Care should be taken when juxtaposing normal, particularly with stereotypical labels, to avoid undue insult.



    (plural normals)
    1. (geometry) A line or vector that is perpendicular to another line, surface, or plane.
    2. (slang) A person who is normal, who fits into mainstream society, as opposed to those who live alternative lifestyles.
    © Wiktionary