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Webster 1913 Edition
Ethmoidal
{ 
Eth′moid
,Eth-moid′al
, }Adj.
 [Gr. [GREEK] like a sieve; [GREEK] sieve + [GREEK] from: cf. F. 
ethmoïde
, ethmoïdal
.] (Anat.) 
(a) 
Like a sieve; cribriform. 
(b) 
Pertaining to, or in the region of, the ethmoid bone. 
Ethmoid bone 
(Anat.)
, a bone of complicated structure through which the olfactory nerves pass out of the cranium and over which they are largely distributed.