The term "weak-sister" is a derogatory way to describe someone who lacks strength or courage. However, there are many other synonyms that can be used to describe a person who is deemed weak or timid. Some possible alternatives include spineless, feeble, faint-hearted, cowardly, pusillanimous, timorous, and chicken-hearted. Each of these words carries slightly different connotations and can be used in various contexts to describe someone who may lack confidence or assertiveness. It's important to remember that using negative language to describe others can be hurtful, and it's always better to focus on positive traits and characteristics instead.