Milquetoast \MILK-tohst \ noun
(sometimes initial capital letter) a very timid, unassertive, spineless person, especially one who is easily dominated or intimidated: a milquetoast who’s afraid to ask for a raise.
And though he said little, he was not by any means a milquetoast; indeed, he was as capable as anyone of manly fury.
— John Gardner, The Sunlight Dialogues, 1972 END: QUOTES
Milquetoast came to English in the 1930s from the character Caspar Milquetoast, who appeared in the comic strip The Timid Soul by American cartoonist H. T. Webster.