古こ細さい菌きんこさいきんMeanings1nounarchaea; archaebacteriaDomain-specific term in biology; refers to a domain of single-celled microorganisms distinct from bacteria.古こ細さい菌きんは極きょく限げん環かん境きょうに生せい息そくするものが多おおい。Many archaea live in extreme environments.