The word "more stout-hearted" refers to someone who is brave, determined, and firm in their beliefs. Antonyms for this phrase would be words that represent the opposite of these qualities. Some possible antonyms include timid, cowardly, faint-hearted, weak-willed, spineless, and hesitant. These words describe individuals who lack courage, confidence, and conviction, and who are easily swayed by fear or doubt. While being "more stout-hearted" is generally seen as a positive trait, it's also important to acknowledge that we all have moments of vulnerability and uncertainty, and that being able to admit and address these feelings is just as important as being brave and resolute.