Acrania: Congenital partial or total absence of the skull.
The only word close to this is acrania...partial or complete absence of all or part of the skull.
. abronia 2. abyssinia 3. acapnia 4. acrania 5. acrodynia 6. acromyotonia 7. actinia 8. adansonia 9. agrimonia 10. agromania 11. agrypnia 12. albania 13. algolagnia 14. allionia 15. allodynia 16. alpinia 17. alstonia 18. amazonia 19. amenia 20. ammonia 21. amnia 22. amphisbaenia 23. amsonia 24. amyotonia 25. andromania 26. anglomania 27. anhedonia 28. aniseikonia 29. ansonia 30. anthomania 31. antigonia 32. antonia 33. aphonia 34. apollonia 35. apophenia 36. aquitania 37. argyrotaenia 38. armenia 39. arthrodynia 40. asthenia 41. atonia 42. avicennia 43. azania 44. babylonia 45. balletomania 46. bartonia 47. bauhinia 48. beatlemania 49. begonia 50. bergenia 51. bibliomania 52. bignonia 53. bithynia 54. bocconia 55. boltonia 56. boronia 57. bosnia 58. bothnia 59. boykinia 60. brasenia 61. britannia 62. bronchopneumonia 63. bryonia 64. burmannia 65. caesalpinia 66. caladenia 67. calandrinia 68. caledonia 69. california 70. campania 71. catalonia 72. catamenia 73. catania 74. catatonia 75. cephalonia 76. ceratonia 77. cetonia 78. charronia 79. chechenia 80. chelonia 81. christiania 82. ciconia 83. cladonia 84. claytonia 85. cleptomania 86. cliftonia 87. clintoni