The Collaborative International Dictionary of English v.0.48:

Squamosal \Squa*mo"sal\ (skw[.a]*m[=o]"sal), a. (Anat.)
   (a) Scalelike; squamous; as, the squamosal bone.
   (b) Of or pertaining to the squamosal bone. -- n. The
       squamous part of the temporal bone, or a bone
       corresponding to it, in many of the lower vertebrates.
       See Temporal bone, under Temporal.
       [1913 Webster] Squamose