1. extension cord an electric cord used to extend the length of a power cord
  2. extension course a course offered as part of an extension service
  3. extension agent an advisor employed by the government to assist people in rural areas with methods of farming and home economics
  4. expense record a written record of money spent
  5. extension ladder a ladder whose length can be extended
  6. extension act of expanding in scope
  7. extension phone an additional telephone set that is connected to the same telephone line
  8. extensional defining a word by listing the class of entities to which the word correctly applies
  9. extension service an educational opportunity provided by colleges and universities to people who are not enrolled as regular students
  10. expansion bolt a bolt that has an attachment that expands as the bolt is driven into a surface
  11. extensor a skeletal muscle whose contraction extends or stretches a body part
  12. expansion slot (computer) a socket in a microcomputer that will accept a plug-in circuit board
  13. extrasensory seemingly outside normal sensory channels
  14. expansionist of or involving or guided by expansionism
  15. extensive large in spatial extent or range or scope or quantity
  16. extortioner a criminal who extorts money from someone by threatening to expose embarrassing information about them
  17. expansion bit a bit with a cutting blade that can be adjusted to different sizes
  18. extinct no longer in existence
  19. Athanasian Creed a Christian profession of faith
  20. exterminator someone who exterminates