Bohemisms or Czechisms' are words and expressions borrowed or derived from the Czech language. The former term is derived from the historical name Bohemia for Czech lands.
Many Bohemisms related to church and liturgy entered Polish language in Middle Ages during the Christianization of Poland under the influence of Moravian and Bohemian traditions. Many of them ultimately originated from Latin language, the language of liturgy.
The analysis of Bohemisms is a significant argument of the Edward L. Keenan's hypothesis about the authorship of The Tale of Igor's Campaign.