1) Having one axis 1) Monaxial 2) Uniaxal 
the optic character of anisotropic minerals, meaning they have one direction of single refraction
• (a.) Having only one axis; developing along a single line or plane; -- opposed to multiaxial. • (a.) Having but one optic axis, or line of no double refraction.
1. <chemistry> Having but one optic axis, or line of no double refraction. ... In uniaxial crystals, the optic axis has the direction of the vertical crystallographic axis. All tetragonal and hexagonal crystals are uniaxial. ... 2. <biology> Having only one axis; developing along a single line or plane; opposed to multiaxial. ... Origin...
(u″ne-ak´se-әl) having only one axis. developed in an axial direction only.
Type: Term Pronunciation: yū′nē-ak′sē-ăl Definitions: 1. Having but one axis; growing chiefly in one direction.
having one axis. · (of a crystal) having one direction in which double refraction does not occur. · (of a plant) having a primary stem that does not branch and that terminates in a flower.