An artificial international language using characters (as mathematical symbols) instead of words to express ideas

Wiktionary Word definitions in Wiktionary
n. (context linguistics English) A writing system where concepts are written instead of words. The system is not phonetic and uses ideograms, such as mathematical symbols. It is intended to be universally understood.

Wikipedia Word definitions in Wikipedia
A pasigraphy (from Greek pasi 'to all' and graph 'write') is a writing system where each written symbol represents a concept (rather than a word or sound or series of sounds in a spoken language). The aim (as with ordinary numerals 1, 2, 3, etc.) is to ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Pasigraphy \Pa*sig"ra*phy\, n. [Gr. ? for all (dat. pl. of ? all) + -graphy.] A system of universal writing, or a manner of writing that may be understood and used by all nations. --Good.