milquetoast

Milquetoast is an expression used to describe someone who is very bland, weak, boring and ineffectual. The origin of the phrase comes from the character Caspar Milquetoast from the 1924 comic strip The Timid Soul as he was very dull and bland in regards to his personality. A person might be called milquetoast who has much of the same personality traits such as being very timid or weak.