Ma'anar ƙamus na kalmar "chemosynthesis" shine tsarin da wasu ƙananan ƙwayoyin cuta, kamar kwayoyin cuta, suke samun makamashi ta hanyar oxidation na inorganic molecules, maimakon daga rana, kamar yadda a cikin photosynthesis. A cikin chemosynthesis, ana samar da makamashi daga halayen sinadarai na mahaɗan inorganic kamar mahadi na sulfur, ammonia, da methane. Yawanci ana yin wannan tsari ta hanyar ƙwayoyin cuta da ake samu a cikin matsanancin yanayi, kamar magudanar ruwa mai zurfin teku ko maɓuɓɓugan zafi, inda hasken rana ba ya samuwa.