para-

American Heritage® Dictionary of the English Language, Fourth Edition

1. Beside; near; alongside: parathyroid.
2. Beyond: paranormal.
3. Incorrect; abnormal: paresthesia.
4. Similar to; resembling: paratyphoid fever.
5. Subsidiary; assistant: paraprofessional.
6. Isomeric; polymeric: paraldehyde.
7. A diatomic molecule in which the nuclei have opposite spin directions: parahydrogen.
8. 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: para-aminobenzoic acid.
9. Parachute; parachutist: paratroops.

Wiktionary

1. beside, near, alongside, beyond
2. abnormal, incorrect
3. resembling
4. In isomeric benzene derivatives, having the two substituents in opposite positions (compare ortho- and meta-.)
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6. Forming words relating to activities carried out with a parachute.

GNU Webster's 1913

1. A prefix signifying alongside of, beside, beyond, against, amiss; as parable, literally, a placing beside; paradox, that which is contrary to opinion; parachronism.
2. A prefix denoting: (a) Likeness, similarity, or connection, or that the substance resembles, but is distinct from, that to the name of which it is prefixed; as paraldehyde, paraconine, etc.; also, an isomeric modification. (b) Specifically: (Organ. Chem.) That two groups or radicals substituted in the benzene nucleus are opposite, or in the respective positions 1 and 4; 2 and 5; or 3 and 6, as paraxylene; paroxybenzoic acid. Cf. Ortho-, and Meta-. Also used adjectively.