The word phobia refers to an irrational fear. English borrowed it from Latin which in turn borrowed it from Greek. In Greek the word is phobos. The terms for the many different kinds of phobias understandably have Greek and Latin roots. A knowledge of Greek and Latin is valuable for deciphering the meanings of the different phobias.
The word photophobia does not refer to a fear of light in the world of medicine. It simply means extreme sensitivity to light. Other common phobias include pyrophobia, pathophobia and xenophobia. They mean the fears of fire, disease and foreigners.
The phobias thermophobia, apiphobia, entomophobia, arithmophobia and acoustiphobia refer to the fears of heat, bees, insects, arithmetic and noise. Another phobia, claustrophobia, is the fear of closed spaces.
A common phobia is undoubtedly the fear of heights. This is known as acrophobia. Another common phobia is the fear of spiders. This is arachnophobia. The fear of men is androphobia and the fear of women is gynaephobia.
Other phobias are zoophobia, autophobia, hemaphobia, noctiphobia, hydrophobia and heliophobia. They are the fears of animals, being alone, blood, night, water and sunlight. The fear of books, bibliophobia, has the same root as in the most widely-read book of all time, the Bible.
An inexplicable fear is a phobia. Many kinds of phobias exist but some are far more common than others. Without question, the fear of heights, acrophobia, is more common than the fear of books, bibliphobia. Another phobia, one that can comprise several, is the fear of fear- phobophobia.