Ortho

Ortho- is a Greek prefix meaning “straight”, “upright”, “right” or “correct”.

Ortho may refer to:

• Ortho, Belgium, a village in the Belgian province of Luxembourg

• List of commonly used taxonomic affixes (ortho-)
• Arene substitution patterns, two substituents that occupy adjacent positions on an aromatic ring
• Chlordane, an organochlorine compound that was used as a pesticide

• Orthogonal, a synonym for perpendicular
• Orthonormal, the property that a collection of vectors are mutually perpendicular and each of unit magnitude
• Orthodrome, a synonym for great circle, a geodesic on the sphere
• Orthographic projection, a parallel projection onto a perpendicular plane

• Orthomyxovirus, a family of viruses to which influenza belongs
• Orthodontics, a specialty of dentistry concerned with the study and treatment of malocclusions
• Orthopedic, the study of the musculoskeletal system
• Ortho-DOT, a psychedelic drug
• Ortho-cept and Ortho Tri-cyclen, kinds of oral contraceptive drug

• Orthodoxy, right (correct) belief
• Orthopraxy, right (correct) action

• Ortho Pharmaceutical, which merged into Ortho-McNeil Pharmaceutical before being bought by Johnson & Johnson
• Ortho-Clinical Diagnostics, a subsidiary of Quidel Corporation
• Ortho, a lawn care and pesticide company owned by the Scotts Miracle-Gro Company

• Orthos (disambiguation)
• Ortho Mode Transducer
• Orthochromatic
• Orthophotography
• Orthoptera