"virus that parasitizes a bacterium by infecting it and reproducing inside it," 1921, from French bactériophage (1917), from bacterio-, combining form of bacteria, + -phage.
Entries linking to bacteriophage
bacteria n.
"unicellular microorganisms which lack an organized nucleus," and sometimes cause disease, 1847, plural of Modern Latin bacterium, from Greek bakterion "small staff," diminutive of baktron "stick, rod, staff, cudgel." So called because the first ones observed were rod-shaped. Introduced as a scientific word 1838 by German naturalist Christian Gottfried Ehrenberg. A classical plural sometimes also erroneously used as a singular.
The Greek word is from a PIE *bak- "staff used for support, peg" (compare Latin baculum "rod, walking stick;" Irish bacc, Welsh bach "hook, crooked staff;" Middle Dutch pegel "peg, pin, bolt"). De Vaan writes, "Since *b was very rare in PIE, and Celtic shows an unexplained geminate, we are probably dealing with a loanword from an unidentified source."
-phage
word-forming element meaning "eater," from stem of Greek phagein "to eat," from PIE root *bhag- "to share out, apportion; to get a share."
phage n.
virus that destroys bacteria, 1917, an abbreviated form of bacteriophage.