squamosalPronunciation: /skwəˈməʊs(ə)l/Definition of squamosal noun Zoology the squamous portion of the temporal bone, especially when this forms a separate bone which, in mammals, articulates with the lower jaw. Origin: mid 19th century: from Latin squamosus (from squama 'scale') + -alsquamosal in other Oxford dictionaries Definition of squamosal in the US English dictionary