One of the ways of forming words in English is by using prefixes: sounds which can be added to the beginning of a word to change its meaning. One of the interesting prefixes in English is “para” which has a number of different meanings.
Para = defense against
One of the meanings of para is defense against. Thus we have parasol (defense against the sun) and parachute (defense against falling). As a side note, the word parachute was first coined in 1785 by the French balloonist Jean-Pierre Blanchard who attached a parachute to a dog and then dropped it from a balloon. The parachute was actually invented in 1783 by Sébastien Lenormand. After demonstrating that the device worked with the dog, Jean-Pierre Blanchard had to use it himself when his hot air balloon ruptured in 1793.
Para = supplementary
Another meaning of para is supplementary. This is seen in the word paraphernalia. Originally the word referred to dowry: when a woman brought her dowry into a marriage, half of the goods belonged to her husband and the rest was considered her personal property. Thus the woman’s portion became paraphernalia from para meaning supplementary and pherne meaning dowry. In the 18th century, the word came to be used to refer to miscellaneous belongings or equipment.
Para = beside
The use of para to mean beside can be seen in the word parallel which refers to two lines beside each other. Other words which are formed with this meaning of para include paralegal (someone who works beside a law professional); and paramedic (someone who works beside a doctor).
Another interesting word that comes from this meaning of para is parasite: feeding beside. In the Roman world a parasite was a person who sat at the table of a superior, earning meals through the use of flattery. In 1727, the word appeared in Chambers Cyclopedia referring to an animal or plant that subsisted at the expense of another organism.
Para = beyond
There are also a couple of interesting examples of para meaning beyond. One of these is paranoia in which para means beyond and the stem comes from the Greek word nous meaning mind. Paranoia came into use during the 19th century as a designation for a mental disorder characterized by delusions.
Paranormal refers to something beyond the normal, something for which there is no rational explanation.
Para = contrary to
The word paradox provides us with an example of para being used to mean contrary to. The Greek word doxa means opinion and thus paradox is contrary to opinion.
There are a number of words in English which look like they might be using the prefix para but their actual etymology comes from elsewhere. These words would include paraffin, parakeet, and paradise.