Noun, pl. glomeruli
1. A network (tuft) of capillaries that performs the first step of filtering blood in the kidneys. (wikipedia.org)
2. A small intertwined group of capillaries within nephrons of the kidney that filter the blood to make urine. (wiktionary.org)
3. Any of several other similar intertwined masses of things. (wiktionary.org)
4. A small intertwined group of capillaries in the malpighian body; glomeruli filter blood during urine formation. A closely knitted structure of capillaries found in vertebrate kidneys that is responsible for filtering the blood, by reabsorbing useful materials and excreting waste materials from the bloodstream and excretory organs. (biology-online.org)
Word origin: From Latin glomerare “to roll up,” from glomus “a ball of thread” (cf. conglomeration).