/ ˌæntibaɪˈɒtɪk; NAmE -ˈɑːtɪk/ noun
[ usually pl. ] a substance, for example penicillin , that can destroy or prevent the growth of bacteria and cure infections :
The doctor put her on antibiotics (= told her to take them) .
► anti·bi·ot·ic adjective :
an antibiotic drug
effective antibiotic treatment
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WORD ORIGIN
mid 19th cent. (in the sense doubting the possibility of life in a certain environment ): from anti- + Greek biōtikos fit for life (from bios life).