When you use the word biological, you're talking about life and living things. You'll recognize the root "bio-," meaning "life," as in biography — the story of someone's life — and biology — the study of living organisms.

The woman who gave birth to you is your biological mother — she's passed her genes on to you and you're related to her, even if somebody else raised you. Anybody you share genes with is your biological relative. Biological cleaning products make use of natural enzymes, and they're supposed to be safe and non-toxic. On the other hand, biological warfare uses bacteria, viruses, and other naturally occurring poisons to injure and kill people.

Definitions of biological
  1. adjective
    pertaining to biology or to life and living things
    synonyms: biologic
  2. adjective
    of parents and children; related by blood
    biological child”
    (of offspring) generated by procreation
    related by blood; not adopted
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    of parents and children; related by adoption
    foster, surrogate
    providing or receiving nurture or parental care though not related by blood or legal ties
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