adj. growing vertically, either upwards or downwards
adj. adjective for orthotropics, e.g., "An orthotropic appliance is one used in orthotropic (facial growth guidance) treatment."
the GNU version of the Collaborative International Dictionary of English
adj. Having the longer axis vertical; -- said of erect stems.
The Century Dictionary and Cyclopedia
In botany, of or pertaining to or exhibiting orthotropism; growing vertically.
Word Usage
"Last, and usually least in effectiveness in my arsenal, are orthotropic substances (in the form of little pills and capsules) commonly known as vitamins or food supplements."