What word describes someone who is lacking initiative or strength of character?

The word that describes someone who is lacking initiative or strength of character is "feckless." It comes from the Scots word "feck," which means to do or to make. In this context, it refers to an individual's inability to take action or show determination, highlighting a sense of ineffectiveness and irresponsibility. Such a person may be seen as passive or dependent on others for decision-making and motivation.

The other choices do not convey the same meaning. "Exigent" refers to something appearing urgent or requiring immediate action, which implies a sense of necessity rather than a lack of initiative. "Robust" describes strength and vigor, particularly in health or character, which is the opposite of lacking strength. "Fracas" denotes a noisy disturbance or quarrel, which has no relation to personal initiative or character strength. Thus, "feckless" is the most fitting word for describing someone who lacks initiative or strength of character.