Webster's Revised Unabridged Dictionary · 1913

icon

icon (ī"kon) , noun

[Latin, from Greek e'ikw`n.]

1.
An image or representation; a portrait or pretended portrait.
Netherlands whose names and icons are published. — Hakewill
2.
(Greek Ch.) A sacred picture representing the Virgin Mary, Christ, a saint, or a martyr, and having the same function as an image of such a person in the Latin Church. The term is used especially for a highly stylized and conventionalized representation of a holy person, rich in symbolism and used in devotional services in many of the eastern Orthodox churches, especially the Greek and Russian Orthodox Churches.
3.
a symbol, especially a symbol whose form suggests its meaning or the object it represents.

In a graphical user interface, pointing to and clicking on an icon may cause any of several types of actions, such as opening a file or executing a program, depending on how the icon properties are defined.

4.
(Computers) a graphical symbol for a data object whose form suggests the nature or function of the object; especially, such a symbol as viewed on the computer screen.
5.
any object of uncritical devotion.
The former congresswoman and Vice-Presidential candidate Geraldine Ferraro is still an icon to many party members. — The New York Times, April 16, 1998
6.
an outstanding example of something which has come to represent the class of things to which it belongs; a paragon; used of persons as well as objects.