# ortho-
## English
### Alternative forms

* orth- (before vowel)

### Etymology

From Ancient Greek ὀρθός (orthós).

### Pronunciation

* (Received Pronunciation) IPA: /ɔː.θə-/, /ɔːˈθɒ-/
* (General American) IPA: /oɹ.θə-/, /oɹˈθɑ-/
* Audio (US):(file)
* Hyphenation: or‧tho-

### Prefix

ortho-
* Right angle, perpendicular.
    In this sense, it is the angle that is "right" or straight rather than the line; orthogon is a right-angle triangle, orthocentric is a tetrahedron where all three pairs of opposite edges are perpendicular, orthoclastic is a crystal whose cleavage planes are at right angles. Synonym: cross-
* Proper, righteous, pure.
    E.g. orthorexia is an unhealthy fixation with healthy or righteous eating, an orthotaxon is a true taxon based biological relationships rather than form, orthology is speech which is proper, orthoquartzite is very pure quartz sandstone. Synonym: eu-
* To correct or fix.
    E.g. orthophotography is the geometrical correction of aerial photographs, orthoptics is the treatment of muscular irregularities of the eye, orthodontics is the correcting of misaligned teeth. Synonym: fix-
* Same, from the same.
    E.g. An orthocousin, unlike a cross-cousin, is on the same side of the family; orthogamy is when a plant's ovules are fertilized by pollen from the same plant; orthochronous is a transformation which preserves the direction of time. Synonym: ipsi-
* Normal, ordinary.
    E.g. orthocclusion is normal occlusion, orthodromic is when neurological impulses are passed in the normal direction, orthogravitropism is the ordinary effect of gravity on plants Synonym: normo-
* Straight in form.
    E.g. orthoconic is a mollusc shell that is straight rather than spiraled, orthodentin is dentin composed of straight tubes, orthognathous is straight-jawed. Synonym: recti-.
* (crystallography) Orthorhombic crystal structure.
    E.g. orthochrysotile is an orthorhombic chrysotile, orthopyroxene is a pyroxene that forms orthorhombic crystals, orthohexagonal is having orthorhombic hexagonal symmetry.
* (organic chemistry) In isomeric benzene derivatives, having the two substituents in adjacent (1,2) positions (compare meta- and para-).
    E.g. orthophenylene, orthosubstitution, orthocleavage.
* (chemistry) Having an extra proportion of water.
    E.g. orthophosphate, orthosilicate, orthoferrite.
* Independent, separate.
    E.g. orthogonal as in statistically independent, orthopair is a pair of disjoint subsets, orthogonal in the sense of two aspects of a software problem are able to be treated separately.
* Original, primary.
    E.g. orthonasal is the first direction from which olfaction happens; orthosteric is the original and unmodulated binding site; orthotone is when a speaker retains the accent. Synonym: proto-
* Parallel lines or columns.
    E.g. orthostyle is a series of columns in architecture, an ortholinear keyboard has the keys aligned in straight columns, an orthographic projection has its rays parallel. Synonym: para-
* (physics) Of any molecule of the form X$_2$ in which the two nuclei have parallel spin.
    E.g. orthopositronium, orthohelium, orthoquarkonium.
* (medicine) Orthopaedics.
    E.g. orthogeriatrics is the combination of orthopaedics and geriatrics, orthosurgeon is an orthopaedic surgeon, orthoroentgenography is orthopedic roentgenography.
* Vertical or upright in movement.
    E.g. orthotropic is to grow vertically (up or down), orthostasis describes the state of the human body in a standing position, orthograde is walking or standing in that position.
* (geology) Igneous.
    E.g. orthogneiss is a gneiss derived from igneous, rather than sedimentary (paragneiss); orthoamphibolite, orthocumulate.Synonym: igneo-

#### Derived terms

* orthobicupola
* orthofluvial
* orthographic
* ortholinear
* orthomegodont
* orthostyle
* orthobiologic
* orthodontics
* orthofacial
* orthokeratology
* ortholinear
* orthometric
* orthopedagogy
* orthopedia
* orthophoto
* orthophotography
* orthopsychiatry
* orthoptics
* orthorectification
* orthorectify
* orthobenzoquinone
* orthocleavage
* orthophenylene
* orthophthalic
* orthoquinone
* orthoselective
* orthosubstitution
* orthoamphibolite
* orthocumulate
* orthogneiss
* orthodiagonal
* orthogonal
* orthomodular
* orthonormalization
* orthopair
* orthoacid
* orthoaluminate
* orthoarsenite
* orthoborate
* orthoferrite
* orthonitrate
* orthonitric acid
* orthoperiodate
* orthoperiodic
* orthophosphate
* orthophosphite
* orthophosphoric acid
* orthosilicate
* orthocclusion
* orthocephalic
* orthochess
* orthodromic
* orthograft
* orthogravitropism
* orthophemistic
* orthophosphoric
* orthopia
* orthoacetate
* orthobenzoate
* orthocarbonate
* orthoester
* orthoformate
* orthogeosyncline
* orthonasal
* orthonym
* orthoradial
* orthosteric
* orthosympathetic
* orthotone
* orthogeriatric
* orthogeriatrics
* orthoroentgenography
* orthosurgeon
* orthosurgery
* orthochrysotile
* orthocomplement
* orthoconglomerate
* orthohexagonal
* orthopinacoid
* orthopinakiolite
* orthopyroxene
* orthosilicate
* orthocharmonium
* orthoexciton
* orthohelium
* orthohydrogen
* orthopositronium
* orthoquarkonium
* ortholinear
* orthoquartzite
* orthoscopic
* orthostereoscopic
* orthostereoscopy
* anorthoclase
* orthocenter
* orthocentral
* orthocentric
* orthoclase
* orthoclastic
* orthodiagonal
* orthodome
* orthodrome
* orthogon
* orthogonal
* orthography
* orthogrid
* orthohedron
* ortholinear
* orthometric
* orthomode
* orthorhombic
* orthoscopy
* orthoslice
* orthotope
* pseudoorthorhombic
* orthochromatic
* orthoevolution
* orthogenesis
* orthogenic
* orthographical
* orthography
* orthology
* orthometry
* orthomolecular
* orthonym
* orthopathy
* orthophony
* orthoploid
* orthoprax
* orthopsychology
* orthorexia
* orthoselection
* orthosexual
* orthosexuality
* orthosomnia
* orthotaxon
* anorthominasragrite
* orthochromatic
* orthochronous
* orthocousin
* orthodata
* orthogamous
* orthogamy
* orthography
* orthogroup
* orthology
* orthoselection
* orthosymmetric
* orthoceratite
* orthochoanitic
* orthoconic
* orthodentin
* orthognathous
* orthomyxovirus
* orthopalinal
* orthosomatic
* orthograde
* orthopnoea
* orthostasis
* orthotropic

### Anagrams

* Rooth, thoro

## Danish
### Prefix

ortho-
* right, proper
    ortodoks
* (organic chemistry) ortho-

#### Coordinate terms

* (organic chemistry): meta-, para-

#### Derived terms
## French
### Etymology

From Ancient Greek ὀρθός (orthós).

### Pronunciation

* IPA: /ɔʁ.to/

### Prefix

ortho-
* right

#### Derived terms

* orthodentie
* orthodentiste
* orthopède
* orthopédie