para-

1. Prefix denoting a departure from the normal. 2. Prefix denoting involvement of two like parts or a pair. 3. Prefix denoting adjacent, alongside, near, etc. 4. (p-) In chemistry, an italicized prefix denoting two substitutions in the benzene ring arranged symmetrically, i.e., linked to opposite carbon atoms in the ring. For words beginning with p. or p-, see the specific name. [G. alongside of, near]

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para- .par-ə, 'par-ə or par- prefix

1) closely related to <paraldehyde>

2) involving substitution at or characterized by two opposite positions in the benzene ring that are separated by two carbon atoms <paradichlorobenzene> abbr. p- compare META- (2), ORTH- (2)

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prefix denoting

1. beside or close to. Example: paranasal (near the nasal cavity).

2. resembling. Example: paradysentery (a mild form of dysentery).

3. abnormal. Example: paralalia (abnormal speech).

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symbol p-; in organic chemistry, a prefix indicating a 1,4-substituted benzene ring, e.g., p-xylene (1,4-dimethylbenzene) or p-nitrophenol (4-nitrophenol).

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