- pertaining to or occupying two adjacent positions in the benzene ring.
- 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).
- 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)).
- straight or upright
- perpendicular or at right angles
- correct or right
- denoting an organic compound containing a benzene ring with substituents attached to adjacent carbon atoms (the 1,2- positions)
- denoting an oxyacid regarded as the highest hydrated form of the anhydride or a salt of such an acid
- denoting a diatomic substance in which the spins of the two atoms are parallel
