Ænon is a Greek word coming from a Hebrew term "ay-yin". It means "spring" or "natural fountain", and was a place near Salem where John the Baptist baptized (John 3:23). Its probable location was near the upper source of the Wadi Far'ah, an open valley extending from Mount Ebal to the Jordan River which is full of springs. There is a now place called Ainun four miles north of the springs.
It is found only once in the Bible, and in reference to baptism. The name is commonly used amongst Baptist organizations and churches.
The Madaba Map shows the location of Ænon, symmetrical with the location of Bethabara (the other place where John the Baptist baptized), across the Jordan.
This article incorporates text from Easton's Bible Dictionary (1897), a publication now in the public domain.