英语词源字典 - 在线词源网站

infest (v.)[infest 词源字典]: late 15c., "to attack, assail, hurt, distress, annoy," from Middle French infester, from Latin infestare "to attack, disturb, trouble," from infestus "hostile, dangerous," originally "inexorable, not able to be handled," from in- "not, opposite of" (see in- (1)) + -festus "(able to be) seized." Sense of "swarm over in large numbers" first recorded c. 1600. Related: Infested; infesting.[infest etymology, infest origin, 英语词源]
mawworm (n.): "worm infesting the stomach," c. 1600, from maw (n.) + worm (n).
moss (n.): Old English meos "moss," related to mos "bog," from Proto-Germanic *musan (cognates: Old High German mios, Danish mos, German Moos), also in part from Old Norse mosi "moss, bog," and Medieval Latin mossa "moss," from the same Germanic source, from PIE *meus- "damp," with derivatives referring to swamps and swamp vegetation (cognates: Latin muscus "moss," Lithuanian musai "mold, mildew," Old Church Slavonic muchu "moss").
Selden Moseþ þe Marbelston þat men ofte treden. ["Piers Plowman," 1362]
All the Germanic languages have the word in both senses, which is natural because moss is the characteristic plant of boggy places. It is impossible to say which sense is original. Scott (1805) revived 17c. moss-trooper "freebooter infesting Scottish border marshes."
trypanosome: "A single-celled parasitic protozoan with a trailing flagellum, infesting the blood", Early 20th century: from Greek trupanon 'borer' + -some³.