All articles starting with O
9,097 articles
Odo of France
Odo (Eudes) of France, c. 856–898, Count of Paris and first non-Carolingian King of West Francia (888–898), hero of the Viking siege of Paris 885–886, elected after Charles the Fat's deposition, rival of Charles the Simple.
Odoacer
Odoacer (Odovacar), c. 433–493, barbarian soldier, son of Edecon, who deposed Romulus Augustulus in 476 and ruled Italy as king for seventeen years until murdered by Theoderic at Ravenna.
Odoardo Farnese
Odoardo Farnese (1573–1626) was an Italian prince of the Farnese family and a cardinal from 1591, remembered as the patron who brought Annibale Carracci to Rome.
Odocoileus
Odocoileus is a North American deer genus (Rafinesque, 1832) holding the white-tailed deer and mule/black-tailed deer, defined by their inter-species hybridization, chronic wasting disease susceptibility, and huge ecological and economic roles.
Odogwu
Odogwu is an Igbo word for a great man, hero, or boss, a traditional chieftaincy title that became everyday Nigerian slang after Burna Boy's 2020 single.
Odometer
An odometer, also called a mileometer or milometer, is an instrument that measures and records the cumulative distance a vehicle travels, shown in the instrument cluster.
Odon Grof
Ödön Gróf (Edmund Grof, 1915–1997), Hungarian freestyle swimmer; 1936 Berlin Olympic bronze in the 4x200 m relay, 1934 European champion, later US-based coach after 1956 defection.
Odon Tersztyanszky
Ödön Tersztyánszky (Precíz Ödön), Hungarian fencer and army officer (1890–1929), double 1928 Olympic sabre champion individually and with the team, 1924 team silver and bronze, left-handed after a POW-camp hand injury, died in a motorcycle accident.
Ödön von Horváth
Ödön von Horváth (1901–1938), born Edmund Josef von Horváth, was an Austrian-Hungarian writer who renewed the Volksstück folk play and wrote the antifascist novel Jugend ohne Gott.
Odon Zombori
Ödön Zombori (Zombori Ödön, born Janicsek), Hungarian wrestler, 1906–1989. Olympic silver 1932 and gold 1936 in bantamweight freestyle; European champion 1931 and 1933; later coached Argentina at the 1956 Olympics.
Odonata
Odonata, the insect order of dragonflies and damselflies (Anisoptera, Zygoptera, Anisozygoptera), about 6,442 species with a 320-million-year fossil record; aquatic larvae, top predators, key freshwater bioindicators, 16% threatened per IUCN 2021.
Odontesthes bonariensis
Odontesthes bonariensis, the pejerrey or Argentinian silverside, is an Atherinopsidae fish of the Río de la Plata basin, key in Argentine fisheries, with temperature-dependent sex determination and aquaculture since 1904.
Odonto-onycho-dermal dysplasia
Odonto-onycho-dermal dysplasia (OODD, OMIM 257980) is a rare autosomal recessive WNT10A ectodermal dysplasia with severe tooth agenesis, cone-shaped teeth, nail dystrophy, palmoplantar hyperkeratosis, and variable sweating changes.
Odontoblast
Odontoblast: dentin-forming cell lining the tooth pulp cavity, derived from neural crest mesenchyme; induced by inner enamel epithelium, secretes predentin, forms sclerotic and reparative dentin, and acts in pulp sensory defense.
Odontochondrodysplasia
Odontochondrodysplasia (ODCD, Goldblatt syndrome, OMIM 184260) is a rare autosomal recessive skeletal dysplasia with dentinogenesis imperfecta, short stature, joint laxity, and platyspondyly, caused by hypomorphic TRIP11 or MIA3 variants.
Odontodactylus scyllarus
Odontodactylus scyllarus, the peacock mantis shrimp, is an Indo-West Pacific smasher stomatopod striking at over 20 m/s with forces up to 1501 N, and has 12 color photoreceptors plus dynamic polarization vision.
Odontogenesis imperfecta
Odontogenesis imperfecta (ODI) is a hereditary tooth-structure disturbance, a generalized genetic defect of enamel and dentine formation; also a former MeSH heading (1965-93) for odontodysplasia and ICD-11 code LA30.9.
Odontoidectomy
Odontoidectomy is a neurosurgical procedure that removes the odontoid process of the second cervical vertebra to relieve compression of the brainstem and upper spinal cord.
Odontology
Odontology (ISSN 1618-1247) is a peer-reviewed English dentistry and craniofacial research journal, official journal of the Society of the Nippon Dental University, published by Springer since 2001 as successor to Shigaku; MEDLINE-indexed, 2025 impact factor 2.6.
Odontometry
Odontometry is the measurement of tooth characteristics (MeSH D009811), covering mesiodistal and buccolingual crown dimensions used in orthodontics, endodontic working-length determination, and forensic estimation of sex, age, and population affinity.
Odontophrynus
Odontophrynus (escuerzos), a genus of 11 semi-fossorial toad-like frogs (Odontophrynidae) from southern and eastern South America, famous for diploid-tetraploid cryptic species in the O. americanus complex.
Odoo
Odoo, formerly OpenERP and TinyERP, is an open-source business management suite developed by the Belgian company Odoo S.A., covering accounting, sales, CRM, inventory, manufacturing, and human resources in free Community and paid Enterprise editions.
Odoptu field
Odoptu (Одопту) is an oil and gas field on the northeastern shelf of Sakhalin Island, Russia, and one of three fields in the Sakhalin-1 project, producing since 2010.
Odor
An odor is the sensation produced when volatile chemical molecules stimulate the olfactory organs, with about 400 functional human receptor genes detecting odorants in mixtures.
Odorant-binding protein
Odorant-binding proteins (OBPs), including pheromone-binding proteins (PBPs), are small soluble proteins in insect sensillar lymph and vertebrate nasal mucus that bind and transport hydrophobic odorants to olfactory receptors; first identified in 1981 in Antheraea polyphemus.
Odorheiu Secuiesc
Odorheiu Secuiesc (Székelyudvarhely), a municipality in Harghita County, Transylvania, on the upper Târnava Mare; former center of Udvarhely Seat, known for Székelytámadt Fortress, its school-city tradition, and Roman-era fort sites.
Odorization
Odorization is the deliberate addition of a strong-smelling odorant to odorless natural gas so leaks are detectable by smell, made standard after the 1937 New London school explosion.
Odorrana
Odorrana (odorous frogs, 臭蛙属) is a ranid frog genus of about 70 stream-dwelling species across East and Southeast Asia, established 1990, type species O. margaretae, with karst-endemic and antimicrobial-peptide members.
Odottemita
Odottemita (踊ってみた), meaning "I tried dancing", is the practice of posting videos of oneself dancing to Vocaloid, anime, or doujin songs, begun on Niconico Douga in 2007.
Odprawa posłów greckich
Odprawa posłów greckich (The Dismissal of the Greek Envoys) is a Renaissance tragedy by Polish poet Jan Kochanowski, first performed in 1578 at a wedding in Ujazdów near Warsaw.