isoquinoline
noun
iso·quin·o·line
| \ ˌī-sō-ˈkwin-ᵊl-ˌēn
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Medical Definition of isoquinoline
: a low-melting nitrogenous base C9H7N that is associated with its isomer quinoline in coal tar and that is the parent structure in many alkaloids (as narcotine and papaverine)