1. A the 1st letter of the Roman alphabet
  2. 100000 the cardinal number that is the fifth power of ten
  3. Abraham the first of the Old Testament patriarchs and the father of Isaac; according to Genesis, God promised to give Abraham's family (the Hebrews) the land of Canaan (the Promised Land); God tested Abraham by asking him to sacrifice his son
  4. 'tween in between
  5. Aachen a city in western Germany near the Dutch and Belgian borders
  6. A-bomb a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239)
  7. AIDS a serious (often fatal) disease of the immune system transmitted through blood products especially by sexual contact or contaminated needles
  8. ASCII (computer science) a code for information exchange between computers made by different companies; a string of 7 binary digits represents each character; used in most microcomputers
  9. Abadan a port city in southwestern Iran
  10. Aaron (Old Testament) elder brother of Moses and first high priest of the Israelites; created the golden calf
  11. A-list a list of names of specially favored people
  12. Aarhus port city of Denmark in eastern Jutland
  13. A-team a group of elite soldiers or a leadership group of advisors or workers in an organization
  14. Abkhaz of or relating to Abkazia or its people or their language
  15. Abdias a Hebrew minor prophet
  16. 1000000 the number that is represented as a one followed by 6 zeros
  17. 1000th the ordinal number of one thousand in counting order
  18. ADHD condition characterized by behavioral and learning disorders
  19. ASEAN an association of nations dedicated to economic and political cooperation in southeastern Asia and who joined with the United States to fight against global terrorism
  20. A.D. in the Christian era