[kuht-l-bohn] 
| the calcareous internal shell of cuttlefishes, used to make powder for polishing and fed to canaries and other pet birds to supply their diet with lime. |
| cut·tle·bone (kŭt'l-bōn') n. The calcareous internal shell of a cuttlefish, used as a dietary supplement for cage birds or ground into powder for use as a polishing agent. [Middle English cotilbone : codel, cotil, cuttlefish; see cuttlefish + bone, bone; see bone.] |
lˌboʊn