Regular

Regular may refer to:

Music

 * "Regular" (Badfinger song)
 * Regular tunings of stringed instruments, tunings with equal intervals between the paired notes of successive open strings

Other uses in arts, entertainment, and media

 * Regular character, a main character who appears more frequently and/or prominently than a recurring character
 * Regular division of the plane, a series of drawings by the Dutch artist M. C. Escher which began in 1936

Language

 * Regular inflection, the formation of derived forms such as plurals in ways that are typical for the language
 * Regular verb
 * Regular script, the newest of the Chinese script styles

Algebra and number theory

 * Regular category, a kind of category that has similarities to both Abelian categories and to the category of sets
 * Regular chains in computer algebra
 * Regular element (disambiguation), certain kinds of elements of an algebraic structure
 * Regular extension of fields
 * Regular ideal (multiple definitions)
 * Regular monomorphisms and regular epimorphisms, monomorphisms (resp. epimorphisms) which equalize (resp. coequalize) some parallel pair of morphisms
 * Regular numbers, numbers which evenly divide a power of 60
 * Regular p-group, a concept capturing some of the more important properties of abelian p-groups, but general enough to include most "small" p-groups
 * Regular prime, a prime number p > 2 that does not divide the class number of the p-th cyclotomic field
 * The regular representation of a group G, the linear representation afforded by the group action of G on itself
 * Regular ring, a ring such that all its localizations have Krull dimension equal to the minimal number of generators of the maximal ideal
 * von Neumann regular ring, or absolutely flat ring (unrelated to the previous sense)
 * Regular semi-algebraic systems in computer algebra
 * Regular semigroup, related to the previous sense
 * *-regular semigroup

Analysis

 * Borel regular measure
 * Cauchy-regular function (or Cauchy-continuous function,) a continuous function between metric spaces which preserves Cauchy sequences
 * Regular functions, functions that are analytic and single-valued (unique) in a given region
 * Regular matrix (disambiguation)
 * Regular measure, a measure for which every measurable set is "approximately open" and "approximately closed"
 * The regular part, of a Laurent series, the series of terms with positive powers
 * Regular singular points, in theory of ordinary differential equations where the growth of solutions is bounded by an algebraic function
 * Regularity, the degree of differentiability of a function
 * Regularity conditions arise in the study of first class constraints in Hamiltonian mechanics
 * Regularity of an elliptic operator
 * Regularity theory of elliptic partial differential equations

Combinatorics, discrete math, and mathematical computer science

 * Regular algebra, or Kleene algebra
 * Regular code, an algebraic code with a uniform distribution of distances between codewords
 * Regular expression, a type of pattern describing a set of strings in computer science
 * Regular graph, a graph such that all the degrees of the vertices are equal
 * Szemerédi regularity lemma, some random behaviors in large graphs
 * Regular language, a formal language recognizable by a finite state automaton (related to the regular expression)
 * Regular map (graph theory), a symmetric tessellation of a closed surface
 * Regular matroid, a matroid which can be represented over any field
 * Regular paperfolding sequence, also known as the dragon curve sequence
 * Regular tree grammar

Geometry

 * Castelnuovo–Mumford regularity of a coherent sheaf
 * Closed regular sets in solid modeling
 * Irregularity of a surface in algebraic geometry
 * Regular curves
 * Regular grid, a tesselation of Euclidean space by congruent bricks
 * Regular map (algebraic geometry), a map between varieties given by polynomials
 * Regular point, a non-singular point of an algebraic variety
 * Regular point of a differentiable map, a point at which a map is a submersion
 * Regular polygons, polygons with all sides and angles equal
 * Regular polyhedron, a generalization of a regular polygon to higher dimensions
 * Regular polytope, a generalization of a regular polygon to higher dimensions
 * Regular skew polyhedron

Logic, set theory, and foundations

 * Axiom of Regularity, also called the Axiom of Foundation, an axiom of set theory asserting the non-existence of certain infinite chains of sets
 * Partition regularity
 * Regular cardinal, a cardinal number that is equal to its cofinality
 * Regular modal logic

Probability and statistics

 * Regular conditional probability, a concept that has developed to overcome certain difficulties in formally defining conditional probabilities for continuous probability distributions
 * Regular stochastic matrix, a stochastic matrix such that all the entries of some power of the matrix are positive

Topology

 * Free regular set, a subset of a topological space that is acted upon disjointly under a given group action
 * Regular homotopy
 * Regular isotopy in knot theory, the equivalence relation of link diagrams that is generated by using the 2nd and 3rd Reidemeister moves only
 * Regular space (or $$T_3$$) space, a topological space in which a point and a closed set can be separated by neighborhoods

Organizations

 * Regular army for military usage
 * Regular Baptists, an 18th-century American and Canadian Baptist group
 * Regular clergy, members of a religious order subject to a rule of life
 * Regular Force for usage in the Canadian Forces
 * Regular Masonic jurisdictions, or regularity, refers to the constitutional mechanism by which Freemasonry Grand Lodges or Grand Orients give one another mutual recognition

People

 * Moses Regular (born 1971), America football player

Science and social science

 * Regular bowel movements, the opposite of constipation
 * Regular economy, an economy characterized by an excess demand function whose slope at any equilibrium price vector is non-zero
 * Regular moon, a natural satellite that has low eccentricity and a relatively close and prograde orbit
 * Regular solutions in chemistry, solutions that diverge from the behavior of an ideal solution only moderately

Other uses

 * Regular customer, a person who visits the same restaurant, pub, store, or transit provider frequently
 * Regular (footedness) in boardsports, a stance in which the left foot leads