ortho–

Also from Answers.com... Cancer Treatments Learn about current and promising cancer treatments.

1. Straight; upright; vertical: orthotropous.
2. Perpendicular: orthorhombic.
3. Correct; correction: orthopsychiatry.
4. The most fully hydrated form of an acid or of its salts: orthoboric acid.
5. Diatomic molecules in which the nuclei have the same spin direction: orthohydrogen.
6. Of or relating to one of three possible isomers of a benzene ring with two attached chemical groups in which the carbon atoms with attached groups are adjacent: ortho-dibromobenzene.

[Middle English, from Old French, from Latin, from Greek, from orthos, straight, correct, right.]

1. Straight; upright; vertical: orthotropic.
2. Correct; correction: orthopsychiatry.
3. Hydrated form of an acid or of its salts: orthoboric acid.
4. Diatomic molecules in which the nuclei have the same direction of spin: orthohydrogen.
5. ortho– (Abbr. o–) Of or relating to one of three possible isomers of a benzene ring with adjacent carbon atoms having attached chemical groups. Usually used in italic: ortho-dibromobenzene.