Which word describes someone who is not noble in character?

The term "ignoble" accurately describes someone who lacks noble characteristics, such as honor, integrity, or moral principles. It conveys a sense of dishonor and suggests a base or lowly nature in contrast to nobility.

Using this term indicates that the person exhibits qualities that are ethically or socially unacceptable, aligning with the concept of being unsavory or unworthy. In contexts involving moral judgment, labeling someone as ignoble highlights their shortcomings in character, behavior, or intention.

The other terms do not fit this specific definition. "Illicit" refers to something that is forbidden by law or rules, generally relating to legality rather than character. "Impair" means to weaken or damage, which does not imply anything directly about moral qualities. "Hospitable" describes someone who is welcoming and friendly, particularly to guests, and does not connect to the idea of nobility or character flaws at all. Thus, "ignoble" stands out as the clear choice for someone lacking noble character.