Where does the word “Milquetoast” come from and What does Milquetoast mean?

The fictitious character Milquetoast, in full, Caspar Milquetoast, was created by the cartoonist H. T. Webster.

The series, continued at intervals through the 1930’s and 1940’s, depicted episodes in the life of “The Timid Soul,” episodes of harrowing nature to a non-assertive, timorous man.

Thus the modern definition of the word Milquetoast is a person who is timid or submissive.