Growing, arising, or originating together at the same time, especially referring to twins or things that are innate or inborn together.
From Latin 'connascens' (con- 'together' + nascens 'being born/arising'), describing things that literally 'grow together' from birth or origin.
Medieval and Renaissance philosophers loved this word because they used it to discuss whether qualities were 'connascent' (born together with something) or acquired separately—it was the technical language of debates about nature versus nurture!
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