para-

para-

1. word element [Gr.], beside; near; resembling; accessory to; beyond; apart from; abnormal.

2. symbol p-. In organic chemistry, indicating a substituted benzene ring whose substituents are on opposite carbon atoms in the ring.

Examples of benzene derivatives with substituents in the para- position. (A), p -xylene (1,4-dimethylbenzene); (B), p -nitrophenol.

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para- or par-

pref.

1. Beside; near; alongside: paranucleus.

2. Beyond: parapsychology.

3. Incorrect; abnormal: paradipsia.

4. Similar to; resembling: paratyphoid.

5. Subsidiary; assistant: paramedical.

6. Isomeric; polymeric: paraldehyde.

7. A diatomic molecule in which the nuclei have opposite spin directions: parahydrogen.

8. Abbr. p- 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 separated by two unsubstituted carbon atoms. Usually in italic: para-bromoiodobenzene.

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para-, par-,

prefix meaning "similar, beside, beyond, supplementary to, disordered": parabiosis, paramedical, paranoia, paraplegia.

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para-

word element. [Gr.] beside, beyond, accessory to, apart from, against. In chemistry, a prefix indicating the substitution in a derivative of the benzene ring of two atoms linked to opposite carbon atoms in the ring; abbreviated p-.