thermophilePronunciation: /ˈθəːmə(ʊ)fʌɪl/Definition of thermophile noun Microbiology a bacterium or other microorganism that grows best at higher than normal temperatures. Derivatives thermophilicPronunciation: /-ˈfɪlɪk/ adjective thermophile in other Oxford dictionaries Definition of thermophile in the US English dictionary