[awr-thoh] /ˈɔr θoʊ/
pertaining to or occupying two adjacent positions in the benzene ring.
Compare 2 , 3 .
a combining form occurring in loanwords from Greek, where it meant “straight,” “upright,” “right,” “correct” (orthodox) and on this model used in the formation of compound words (orthopedic).
straight or upright: orthotropous
perpendicular or at right angles: orthoclastic
correct or right: orthodontics, orthodox, orthography, orthoptics
(often in italics) denoting an organic compound containing a benzene ring with substituents attached to adjacent carbon atoms (the 1,2- positions): orthodinitrobenzene, o- Compare oarsman Compare oarsman
denoting an oxyacid regarded as the highest hydrated form of the anhydride or a salt of such an acid: orthophosphoric acid See meta- (sense 6)
denoting a diatomic substance in which the spins of the two atoms are parallel: orthohydrogen See para-1 (sense 8)
before vowels orth-, word-forming element meaning “straight, upright, rectangular, regular; true, correct, proper,” now mostly in scientific and technical compounds, from Greek ortho-, stem of orthos “straight, true, correct, regular,” from PIE *eredh- “high” (cf. Sanskrit urdhvah “high, lofty, steep,” Latin arduus “high, steep,” Old Irish ard “high”).
ortho- or orth-
American Orthopsychiatric Association
[awr-oh-bang-key-shuh s, or-] /ˌɔr oʊ bæŋˈkeɪ ʃəs, ˌɒr-/ adjective 1. belonging to the Orobanchaceae, the broomrape family of plants. /ˌɔːrəʊbæŋˈkeɪʃəs/ adjective 1. of, relating to, or belonging to the Orobanchaceae, a family of flowering plants all of which are root parasites, including broomrapes
mathematics, tool A system for symbolic mathematics, especially General Relativity, written by A. Krasinski of Warsaw in the early 1980s. (1995-04-12)
[awr-thuh-sen-ter] /ˈɔr θəˌsɛn tər/ noun, Geometry. 1. the point of intersection of the three altitudes of a triangle.
/ˈɔːθəʊˌsɛntə/ noun 1. the point of intersection of any two altitudes of a triangle