• (a.) On either side of the axis of the skeleton.
<microscopy> Referring to the spacing of rays closely surrounding the principal axis of a lens system. ... See: eyepiece, parfocal. ... (05 Aug 1998) ... 
Lying along an axis - commonest use is in reference to paraxial mesoderm, the mesoderm that forms somites as opposed to the axial mesoderm that forms notochord.
Par·ax'i·al adjective [ Prefix para- + axial .] (Anat.) On either side of the axis of the skeleton. 
Type: Term Pronunciation: par-ak′sē-ăl Definitions: 1. By the side of the axis of any body or part.