par(a)-1 Also p-.
Beside; adjacent to.
[Greek para, beside.]
A number of words from Greek contain this form: parallel (Greek parallēlos, from para, alongside, plus allēlos, one another); paragraph (Greek paragraphos, a short horizontal stroke written below the beginning of a line in which a break of sense occurs, from graphein, write). The Greek form often had a sense of something amiss, faulty, irregular, or subsidiary, which appears in parasite (Greek parasitos, eating at another's table, from sitos food); parish (literally a subsidiary place, from Greek oikos, dwelling); and parody (Greek parōidia, a burlesque poem, from ōidē, an ode).
The sense of something irregular, or outside what is considered normal, appears in several English words: parapsychology, the study of mental phenomena outside orthodox scientific psychology, such as hypnosis or telepathy; paranormal, of topics such as telekinesis or clairvoyance that are beyond the scope of normal scientific understanding; parainfluenza, a disease caused by any of a group of viruses which resemble influenza; paramagnetic, of something very weakly attracted by the poles of a magnet, but not retaining any permanent magnetism; paranoia (Greek noos, mind, hence ‘irregular mind’), a mental condition characterized by delusions of persecution; parasuicide, apparent attempted suicide without the actual intention of killing oneself.
The form is also used for occupational roles considered to be ancillary or subordinate; paramedic, a person who is trained to do medical work, but is not a fully qualified doctor; paralegal, a person trained in subsidiary legal matters but not fully qualified as a lawyer; a more general term is paraprofessional. Such terms are in general more common in North America than in Britain. Sometimes the sense is of something irregular: paramilitary, of an unofficial force organized on military lines.
Para- can refer to something beside or adjacent, as in parathyroid, a gland next to the thyroid; parhelion (Greek hēlios, sun), a bright spot in the sky appearing on either side of the sun; paracrine (Greek krinein, to separate), of a hormone which has effect only in the vicinity of the gland secreting it.
In chemistry, the form indicates that a benzene ring has been substituted at diametrically opposite carbon atoms, as in paradichlorobenzene, a moth repellent, and para-aminobenzoic acid, a crystalline acid which has been used to treat rickettsial infections. It is frequently abbreviated to p- (p-xylene; p-nitrotoluene). Substitution in other positions is indicated by ortho- and meta-. In chemical compounds such as paraformaldehyde, paraldehyde, and paranthracene, whose molecules do not contain benzene rings, para- is used unsystematically in the sense of ‘altered’ to refer to a polymer of the compound.
Some words do not belong here: pariah comes from Tamil; parade from Latin parare, prepare; paradise from a Persian word meaning an enclosed space; paramour from Old French par amour, by love.