Johann(es) Schreck, also Terrenz or Terrentius Constantiensis, Deng Yuhan Hanpo 鄧玉函, Deng Zhen Lohan, (1576, Bingen, Baden-Württemberg or Constance – 11 May 1630, Beijing) was a German Jesuit, missionary to China and polymath. He is credited with the discovery of the scientific-technical terminology.
Schreck studied medicine starting 1590 at the Albert Ludwigs University of Freiburg, the University of Altdorf and after 1603 in Padua. He became a highly respected medic and was affiliated to the scientific society the Accademia dei Lincei in Rome, whose other members included Galileo Galilei. At this academy he worked on the encyclopaedia of botany Rerum medicarum Novae Hispaniae Thesaurus alongside Francisco Hernández de Toledo.
To everyone's surprise (Galileo wrote: "Una gran perdita" - "a big loss"), Schreck became a Jesuit, to go to China as a missionary. He met the Belgian Pater Nicolas Trigault in 1614, with whom he prepared his scientific mission. He started his journey to China in April 1618 from Lisbon. After several pirate incidents and epidemics Schreck arrived in October 1618 in Goa, where he began his opus Plinius Indicus, a botanic and zoological encyclopaedia about Asia, which he was never able to finish. On 22 July 1619 they reached Macau. In 1621 he arrived in Hangzhou, and in late 1623 Beijing.
Schreck was able to achieve enormous language skills; he was fluent in German, Italian, Portuguese, French and English. He wrote his letters in Latin. He also mastered the source languages of Christianity, namely Greek, Hebrew and Biblical Aramaic. Later in his life, he learned Chinese.