acid–fast

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adjective ac·id–fast \ˈa-səd-ˌfast\

Definition of acid–fast

  1. :  not easily decolorized by acids

1903

First Known Use of acid–fast

1903


Medical Dictionary

acid–fast

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adjective ac·id–fast \ˈas-əd-ˌfast\

Medical Definition of acid–fast

  1. :  not easily decolorized by acids (as when stained)—used especially of bacteria and tissues

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