The word "most stannic" is an adjective that refers to an increased level of the chemical element tin. Some synonyms for this term include "most tinny," "most tinlike" and "most tinuous." These words all convey the sense of something being highly associated with the element tin, whether in terms of its appearance, behavior, or composition. Other synonyms that may be used in certain contexts include "most metallic," "most shiny," and "most lustrous." Whatever word you use, it's important to choose one that accurately conveys the meaning you want to express while remaining consistent with the context and tone of your writing.