from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having equal diameters or axes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having an equal or nearly equal diameter in all directions
from the GNU version of the Collaborative International Dictionary of English
- adj. Developed alike in the directions of the several lateral axes; -- said of crystals of both the tetragonal and hexagonal systems.
- adj. Having the several diameters nearly equal; -- said of the cells of ordinary parenchyma.
from The Century Dictionary and Cyclopedia
- Having equal diameters, or being of equal diameter.
Sorry, no etymologies found.
They are more or less angular, and while elongated transversely at first, become nearly isodiametric as the pileus becomes fully expanded, passing from an elongated form to rectangular, or sinuous in outline, the margin more or less upturned, especially in age, when they begin to loosen and "peel" from the surface of the cap.