ortho-

Definition

Right angle, perpendicular.

Etymology

Learned borrowing from Ancient Greek ὀρθός (orthós).

Example Sentences

• "In this sense, it is the angle that is "right" or straight rather than the line; orthogon is a right-angle triangle, orthocentric is a tetrahedron where all three pairs of opposite edges are perpendicular, orthoclastic is a crystal whose cleavage planes are at right angles."
• "E.g., orthorexia is an unhealthy fixation with healthy or righteous eating, an orthotaxon is a true taxon based biological relationships rather than form, orthology is speech which is proper, orthoquartzite is very pure quartz sandstone."
• "E.g., orthophotography is the geometrical correction of aerial photographs, orthoptics is the treatment of muscular irregularities of the eye, orthodontics is the correcting of misaligned teeth."