Agglutinins

Part of speech: noun

Definitions

1. A type of protein that causes particles, such as bacteria or red blood cells, to clump together in a process known as agglutination
2. Molecules found in the immune system that assist in the clumping of cells or pathogens, aiding in immune responses
3. Substances that promote the aggregation of similar cells or materials, often used in blood typing and medical diagnostics

Etymology: The word "agglutinin" is built from "agglutinate" plus the suffix "-in", the common chemical-name ending used for protein-like substances. "Agglutinate" comes from Latin "agglūtinātus", the past participle of "agglūtināre", meaning "to glue to" or "to stick together", which is itself made from "ad-" ("to") and "glūtināre" ("to glue"). That Latin verb grew from "glūtinum", "glue", a word tied to the older Latin "gluten", so the same root that gives English "gluten" sits behind this one. The sticking sense is literal in the original. Latin speakers used "glūten" for a sticky substance, and "agglūtināre" described things being fixed together with glue. English adopted "agglutinate" with that physical meaning, and the chemical extension came later. The suffix "-in" was added to name a substance responsible for the effect, so an agglutinin is, in effect, a "stick-together" substance.