Symbols.com
The world's largest online encyclopedia of graphic symbols, ranging from ideograms carved in mammoth teeth by Cro-Magnon men, to hobo signs and subway graffiti.

Dictionary of Symbolism
An online aid for exploring the meanings of symbols.

Byzant - Esoteric Symbols
Discusses and illustrates a range of powerful and profound religious and esoteric symbols from both Western and Eastern traditions.

Review of Liungman's Dictionary of Symbols
Critical review by Seth Maislin, indexer and information architect.

Blissymbol Dictionary
Comprehensive online dictionary of the Blissymbolics Language - used by linguistically disabled persons.