The insert/overtype mode toggling is not global for the computer or even for a single application but rather local to the text input window in which the Insert key was pressed.
Wiktionary (0.00 / 0 votes) Rate this definition: high fructose corn syrup (Noun). Any of many corn syrups that has undergone an enzymatic processing to convert some of its glucose into fructose to produce a desired sweetness. Origin: high + fructose + corn syrup.
To make the corn syrup into high fructose corn syrup, you turn some of its glucose molecules into fructose molecules by exposing the syrup to yet another enzyme, again produced by bacteria. This enzyme converts the glucose to a mixture of about 42 percent fructose and 53 percent glucose, with some other sugars as well.