1) Anatomical cavities 2) Bone cavities 3) Bone chambers 4) Bony cavities, anatomically 5) Cavities in bones 6) Cavities, of a sort 7) Latvian feminine given name 8) Plural of antrum 9) Sinus cavities 10) Sinuses 11) Sinuses or Roman halls 12) The sinuses Found on https://www.crosswordclues.com/clue/antra