from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Shaped like a bunch of grapes. Used especially of mineral formations: botryoidal hematite.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having the form of a bunch of grapes.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. resembling a cluster of grapes in form
He has a face of that rubicund, knobby type I have heard an indignant mineralogist speak of as botryoidal, and about it waves a quantity of disorderly blond hair.
Labradorite, Charoite, botryoidal chalcedony, and rocs, adn rocs, adn uh, smammie, uze gittin BORIN agin… sari….. and dey maeks handii howz-wholed wepenz.. sew dere, thwak.
Not the least curious part of this outcrop is the black thread of iron silicate which, broken in places, subtends it to the east: some specimens have geodes yielding brown powder, and venal cavities lined with botryoidal quartz of amethystine tinge.
A translucent botryoidal calamine banded with blue and green is found at Laurion in Greece, and has sometimes been cut and polished for small ornaments such as brooches.
The sixth is the "hyalite," which has but a glassy or vitreous lustre, and is found almost exclusively in the form of globules, or clusters of globules, somewhat after the form and size of bunches of grapes; hence the name "botryoidal" is often applied to this variety.
But the heavy, true alluvial gold, in great pure masses, mammillary, or botryoidal (like a bunch of grapes) in shape, have assuredly been formed by accretion on some metallic base, from gold salts in solution, probably chloride, but possibly sulphide.
It consists of a connective tissue and muscular coating, with an internal soft matrix much resembling botryoidal tissue, traversed by fibrous trabeculne (= beams, planks) containing blood-vessels, and the whole organ is gorged with blood, particularly after meals.
They occur in great numbers in a tissue called, botryoidal tissue (Figure XIV.), which occurs especially in masses and patches along the course of the alimentary canal, in its walls.
The matrix of botryoidal tissue is a network of stretched and hollowed connective tissue cells -- it is not a secretion, as cartilage matrix appears to be.
A botryoidal fragment of hematite found in a grave reminds me that in the so-called Antelope rock  at Walpi, around which the Snake dancers biennially carry reptiles in their mouths, there is in one side a niche in which is placed a much larger mass of that material, to which prayers are addressed on certain ceremonial occasions, and upon which sacred meal and prayer emblems are placed.
Archeological Expedition to Arizona in 1895 Seventeenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1895-1896, Government Printing Office, Washington, 1898, pages 519-744