The Synonymous Words for "Sleep" This Is Appendix 171 From The Companion Bible.    There are two words rendered "Sleep" :- katheudo = to compose one's self for sleep. Occurs twenty-two times: never used in death. koimaomai = to fall asleep (unintentionally). Hence this latter is used of death, as it is involuntary, while katheudo is voluntary. See this difference illustrated in 1 Thessalonians 4:14 (where it is koimaomai), and 5:6, 7, 10 (where it is katheudo). Occurs eighteen times; always of death, save Matthew 28:13. Luke 22:45. John 11:12. Acts 12:6.