orthocenter
One of the centers (UK:centres) of a triangle, defined as being the intersection of its three altitudes; in an acute triangle, it is inside the triangle; in an obtuse triangle, it is outside the triangle; in a right-angled triangle it is the vertex opposite the hypotenuse and so is on the triangle.

orthocenters
plural of orthocenter

orthocentre
Alternative form of orthocenter.

orthocentres
plural of orthocentre

orthocephaly
The condition of being orthocephalic

orthocharmonium
The form of charmonium in which the spins of the two quarks are parallel.

orthochromasia
Synonym of orthochromasy.

orthochromasy
The property of a stain to not change color when binding to something else.

orthochromatism
Quality of being orthochromatic.

orthocleavage
cleavage of 1,2 substituents

orthocone
A long straight shell of a nautiloid cephalopod.

orthocones
plural of orthocone

orthocousin
Any of two or more cousins who are the children of siblings of identical gender, i.e. children of brothers or of sisters.

orthocousins
plural of orthocousin

orthod
A form of orthic spodosol.

orthodiagraphy
Examination by means of an orthodiagraph.

orthodontology
Orthodontics.

orthodonture
Orthodontics.
A set of orthodontic braces.

orthodontures
plural of orthodonture

orthodoxality
The quality of being orthodox.

orthodoxism
Strict orthodoxy.

orthodoxisms
plural of orthodoxism

orthodoxization
The process of making orthodox.

orthodoxness
The state or condition of being orthodox.

orthodoxy
Correctness of doctrine and belief in regard to any doctrinal (i.e. philosophical or theological) system.
Conformity to established and accepted beliefs (usually of religions).

orthodromy
Navigation based on calculating the shortest distance between two locations on a globe or sphere.

orthoepie
Obsolete form of orthoepy.

orthoepies
plural of orthoepy

orthoepy
The study of pronunciation.
Accepted or customary pronunciation.

orthoevolution
orthogenesis

orthogenetics
orthogenesis

orthognathism
The quality of being orthognathous.

orthognathy
The condition of being orthognathous

orthogon
A right-angle triangle.
A rectangular figure.
A multi-dimensional figure in which all sides result in a right-angle, typically surpassing the restrictions of 3 dimensions.

orthogonalisation
Alternative spelling of orthogonalization.

orthogonalisations
plural of orthogonalisation

orthogonalities
plural of orthogonality

orthogonality
The property of being orthogonal.

orthogonalization
The process of converting a set of functions or vectors into orthogonal ones.
the process of splitting a problem or system into its distinct components.

orthogonalizations
plural of orthogonalization

orthogons
plural of orthogon

orthograph
An orthographic projection.

orthographs
plural of orthograph

orthogravitropism
The normal tendency of a plants parts to bend downward under the effects of gravity

orthogrid
A structure similar to an isogrid but having rectangular rather than triangular openings.

orthogrids
plural of orthogrid

orthokinesis
A form of kinesis in which the speed of movement of the individual is dependent upon the intensity of the stimulus.

ortholinearity
The state of being ortholinear.

orthologization
The process of rendering something orthologous.

orthology
Correct speaking or the correct use of words.
Homologous sequences descended from the same ancestral sequence for which function of the gene or sequence has been conserved across evolutionary time.

orthometry
The art or practice of constructing verses correctly or harmoniously; the rules of correct poetry.

orthomodularity
The condition of being orthomodular

orthomorphism
A morphism that is also a permutation

orthomorphisms
plural of orthomorphism

orthonectid
Any of the Orthonectida, a small phylum of parasites of marine invertebrates.

orthonectids
plural of orthonectid

orthonormalisation
Alternative spelling of orthonormalization.

orthonormalisations
plural of orthonormalisation

orthonormalities
plural of orthonormality

orthonormality
The condition of being orthonormal

orthonormalization
A form of orthogonalization in which the resulting vectors are all unit vectors

orthonormalizations
plural of orthonormalization

orthopaedia
Alternative spelling of orthopedia.

orthopair
A pair of orthogonal or disjoint subsets (of a given universe)

orthopairs
plural of orthopair

orthopantomography
A form of radiography that produces panoramic images of the mouth.

orthopedagogy
The teaching of correct behaviour

orthopedia
The branch of medicine which deals with the prevention and correction of deformities in bodies; orthopedics.

orthophemism
An orthophemistic term, one that is neither euphemism nor dysphemism.

orthophemisms
plural of orthophemism

orthophony
The art of correct articulation / speaking

orthophotoquad
A quadrangle of orthophotos

orthoplasy
A theory of evolution, stating that that individual modifications supplement, protect, or screen organic characters and keep them alive until useful congenital variations arise and survive by natural selection, and that this process, combined in many cases with 'tradition', gives direction to evolution.

orthopositronium
The state of a positronium exotic atom in which the positron and electron have parallel spins

orthopraxies
plural of orthopraxy

orthopraxy
Correctness of practice or action in regard to religion and especially religious ritual, particularly in juxtaposition to "correct doctrine", or "correct belief" (that is, "orthodoxy").
Right belief combined with right practice, with the emphasis on the latter, often in Latin American liberation theology, contrasting with an orthodoxy seen as insufficiently interested in the practical and political content of faith.

orthoprism
A prism which has its faces parallel to its vertical axis.

orthoprisms
plural of orthoprism

orthopsychology
An approach to psychology focusing on positive human traits such as love, creativity, and personal autonomy.

orthopteran
Any of many insects of the order Orthoptera.

orthopterans
plural of orthopteran

orthopteroid
Any of the insects historically included in the order Orthoptera, including the cockroaches, earwigs, praying mantises, etc.

orthopteroids
plural of orthopteroid

orthopterology
The scientific study of the Orthoptera.

orthopteron
Alternative form of orthopteran.

orthopterons
plural of orthopteron

orthoquarkonia
plural of orthoquarkonium

orthoquarkonium
A form of quarkonium where the spins of the constituent quarks are parallel.

orthorectification
The processing of an aerial photograph by orthorectifying it.
The orthophoto that is produced by this process.

orthorectifications
plural of orthorectification

orthorhombicity
The condition of being orthorhombic

orthoroentgenography
orthopedic roentgenography

orthoselection
The hypothesis that posits that orthogenesis works by means of natural selection.
The acquisition of a common series of rearrangements within a genetic lineage.

orthosexuality
The orthodox or socially accepted form of sexuality or sexual expression in a particular culture.

orthostasis
The act or status of standing upright.
Ellipsis of orthostatic hypotension.

orthostatism
Synonym of orthostasis (“an upright standing position”).

orthostereoscopy
The production of a three-dimensional image free from distortion

orthosterism
The condition of being orthosteric

orthostichies
plural of orthostichy

orthostichy
A row of leaves along a stem

orthostrophy
The condition of being orthostrophic.

orthosurgery
Orthopedics or orthopedic surgery.

orthotenies
plural of orthoteny

orthoteny
The study of straight lines, especially in regards to the flight paths that UFOs tend to follow.

orthotetrahedra
plural of orthotetrahedron

orthotetrahedron
A tetrahedron with three pairs of faces at right angles to one another.