Psycharis was born to a Greek family in Odessa, Ukraine, Imperial Russia on the coast of the Black Sea. Nicholas I of Russia still reigned at the time of his birth and his government exercised censorship and other controls over education, publishing, and all manifestations of public life.
Psycharis lived most of his adult life in Paris where he was employed as a professor.
Psycharis is famous for his coinage of the term diglossia, which describes the split between the prestige dialect and lower-prestige dialects of the same language.
Psycharis also proposed an innovative orthography for Greek which never really caught on, despite being the focus of several serious attempts at implementation continuing into the late 20th century. A beginning Modern Greek textbook for foreign students, Ellinika Tora (Greek Now), employs some of his suggestions such as substituting "lambda" for "rho" when the pronunciaton of the glide is conditioned by the other sounds around it - thus αδερφός (aderfos) instead of standard αδελφός (adelphos). While this and other of his suggestions more accurately reflect true pronunciation, they seem to have little chance of being adopted.