symbiont
noun
sym·bi·ont ˈsim-bē-ˌänt 
: an organism living in symbiosis
especially : the smaller member of a symbiotic pair
Example Sentences
Recent Examples on the Web When Shori takes on another male symbiont, Wright punches a hole in the wall. 
Lovia Gyarkye, The Atlantic, 1 Feb. 2022 Jenkins suspected that this stabilizing mechanism might involve the organisms’ RNA because his colleagues had noticed many regions of strong similarity between host and symbiont transcripts floating around in the cytoplasm. Quanta Magazine, 7 June 2021 Simon says the cicada is trapped in a 17-year cycle that has forced it to make unusual adaptations like living with this symbiont. Eric Niiler, Wired, 21 May 2021 Butler suggests that the Ina-symbiont relationship might be no worse than the forms of dependency that humans already take for granted. Julian Lucas, The New Yorker, 8 Mar. 2021 One symbiont found in Costa Rica was hiding in plain sight: a beetle that clamps its mandibles around the ant’s middle and rides along, looking like a double-vision version of the ant’s backside. National Geographic, 11 Aug. 2020 Still, a team led by CSIRO’s Patrick Buerger wondered if there might be a way to help, at least to some extent, by raising heat-tolerant strains of the corals’ symbionts. Scott K. Johnson, Ars Technica, 14 May 2020 Certain algae species serve as symbionts for Cassiopea jellyfish, providing the animals with nutrients harvested from sunlight by way of photosynthesis. Cheryl Ames, National Geographic, 13 Feb. 2020 In other sap-sucking insects, symbionts serve additional functions, Moran and her colleagues discovered. Elizabeth Pennisi, Science | AAAS, 14 Nov. 2019 See More
Lovia Gyarkye, The Atlantic, 1 Feb. 2022 Jenkins suspected that this stabilizing mechanism might involve the organisms’ RNA because his colleagues had noticed many regions of strong similarity between host and symbiont transcripts floating around in the cytoplasm. Quanta Magazine, 7 June 2021 Simon says the cicada is trapped in a 17-year cycle that has forced it to make unusual adaptations like living with this symbiont. Eric Niiler, Wired, 21 May 2021 Butler suggests that the Ina-symbiont relationship might be no worse than the forms of dependency that humans already take for granted. Julian Lucas, The New Yorker, 8 Mar. 2021 One symbiont found in Costa Rica was hiding in plain sight: a beetle that clamps its mandibles around the ant’s middle and rides along, looking like a double-vision version of the ant’s backside. National Geographic, 11 Aug. 2020 Still, a team led by CSIRO’s Patrick Buerger wondered if there might be a way to help, at least to some extent, by raising heat-tolerant strains of the corals’ symbionts. Scott K. Johnson, Ars Technica, 14 May 2020 Certain algae species serve as symbionts for Cassiopea jellyfish, providing the animals with nutrients harvested from sunlight by way of photosynthesis. Cheryl Ames, National Geographic, 13 Feb. 2020 In other sap-sucking insects, symbionts serve additional functions, Moran and her colleagues discovered. Elizabeth Pennisi, Science | AAAS, 14 Nov. 2019 See More Word History
Etymology
borrowed from German Symbiont, probably altered (after Greek ont-, stem of ṓn, present participle of eînai "to be") from symbiount-, stem of symbiôn, present participle of symbioûn "to live together" — more at symbiosis
First Known Use
1887, in the meaning defined above
Medical Definition
symbiont
noun
sym·bi·ont ˈsim-ˌbī-ˌänt -bē-
-bē- : an organism living in symbiosis
especially : the smaller member of a symbiotic pair
called also symbiote