phentetiothalein
noun
phen·tet·io·tha·lein
| \ ˌfen-ˌtet-ī-ō-ˈthal-ē-ən, -ˈthāl-
\
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Medical Definition of phentetiothalein
: a substance or its disodium salt C20H8I4Na2O4 isomeric with iodophthalein used especially formerly as a radiopaque medium in cholecystography and in tests of liver function
— called also phenoltetraiodophthalein