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.
- 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-.
- 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 (H3BO3) and potassium orthoborate (K3BO3)); if the acid ends in -ous, the corresponding salt ends in -ite (orthoantimonous acid (H3SbO3) and potassium orthoantimonite (K3SbO3)).
Also
especially before a vowel,
orth-.
Origin of ortho-
< Greek, combining form of
orthós straight, upright, correct
Words nearby ortho-
British Dictionary definitions for ortho-
ortho-
before a vowel orth-
combining form
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 Abbreviation: 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- (def. 6)
denoting a diatomic substance in which the spins of the two atoms are parallel
orthohydrogen See para- 1 (def. 8)
Word Origin for ortho-
from Greek
orthos straight, right, upright
Medical definitions for ortho-
ortho-
pref.
Straight; upright; vertical:orthotropic.
Correct; correction:orthopsychiatry.
Hydrated form of an acid or of its salts:orthoboric acid.
Diatomic molecules in which the nuclei have the same direction of spin:orthohydrogen.
Of or relating to one of three possible isomers of a benzene ring with adjacent carbon atoms having attached chemical groups:ortho-dibromobenzene.