natural kind
"natural" grouping, not an artificial one; family of entities possessing properties bound by natural law
en-US/ˈnæt͡ʃɚəl ˈkaɪnd/
en-GB/ˈnæt͡ʃəɹəl ˈkaɪnd/
"natural" grouping, not an artificial one; family of entities possessing properties bound by natural law