ORTHO Definition & Meaning

ortho

[ awr-thoh ]

Phonetic (Standard)IPA

Chemistry.

pertaining to or occupying two adjacent positions in the benzene ring. Compare meta ³, para ³.

ortho-

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 ).
Chemistry.
1. a combining form used in the name of that acid in a given series of acids that contains the most water ( orthoboric acid ). Compare meta-, pyro-.
2. a combining form used in the names of the salts of these acids: if the acid ends in -ic, the corresponding salt ends in -ate ( orthoboric acid (H 3 BO 3 ) and potassium orthoborate (K 3 BO 3 )); if the acid ends in -ous, the corresponding salt ends in -ite ( orthoantimonous acid (H 3 SbO 3 ) and potassium orthoantimonite (K 3 SbO 3 )).

ortho-

straight or upright
orthotropous
perpendicular or at right angles
orthoclastic
correct or right
orthodox
orthodontics
orthoptics
orthography
often in italics denoting an organic compound containing a benzene ring with substituents attached to adjacent carbon atoms (the 1,2- positions) o- Compare oarsman Compare oarsman
orthodinitrobenzene
denoting an oxyacid regarded as the highest hydrated form of the anhydride or a salt of such an acid See meta-
orthophosphoric acid
denoting a diatomic substance in which the spins of the two atoms are parallel See para- 1
orthohydrogen

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Origin of ortho¹

First recorded in 1875–80; independent use of ortho-

Origin of ortho²

< Greek, combining form of �ǰ��ٳ�ó�� straight, upright, correct

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Origin of ortho¹

from Greek orthos straight, right, upright

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