Know how to use "fewer" and "less"? Find out.
medical word-forming element, from Greek histos "warp, web," literally "anything set upright," from histasthai "to stand," from PIE *sta- "to stand" (see stet). Taken by 19c. medical writers as the best Greek root from which to form terminology for "tissue."
histo- or hist-
Body tissue: histogenesis.