Now, this one is difficulter to explain so as to memorize- Milquetoast.
Yes, you got it right. Milk plus toast. A noun here, which means- a spineless or a timid guy. The word's origin is not even hundred year old, and comes from a character called Caspar Milquetoast, the protagonist of the cartoon strip The Timid Soul, by American cartoonist, H. T. Webster.
I will strongly suggest looking at a few cartoons to eternally memorize the meaning of the word.