opsonin

noun

op·​so·​nin ˈäp-sə-nən 

: any of various proteins (such as antibodies or complement) that bind to foreign particles and cells (such as bacteria) making them more susceptible to the action of phagocytes

Word History

Etymology

Latin opsonare to buy provisions, cater (from Greek opsōnein) + English -in entry 1 — more at oligopsony

First Known Use

1903, in the meaning defined above

Medical Definition

opsonin

noun

op·​so·​nin ˈäp-sə-nən 

: any of various proteins (as complement or antibodies) that bind to foreign particles and microorganisms (as bacteria) making them more susceptible to the action of phagocytes