Crypto-Calvinism is a term for Calvinist influence in the Lutheran Church during the decades just after the death of Martin Luther (1546). It denotes what was seen as a hidden (crypto from Greek: κρύπτω meaning "to hide, conceal, to be hid") Calvinist belief, i.e. the doctrines of John Calvin, by members of the Lutheran Church. The term applied to those Germans, who secretly held or were accused of holding the Calvinist doctrine of the Eucharist.
The term crypto-Calvinist in Lutheranism was preceded by terms Zwinglian and Sacramentarian.
Also, Jansenism has been accused of crypto-Calvinism by Roman Catholics.
Read more about Crypto-Calvinism: Background, Philippism, In Saxony, In Scandinavia, Later History and Evaluation