Unsteadfast is a term commonly used to describe someone or something that is unreliable, inconsistent or unfaithful. Its antonyms include terms such as dependable, consistent, reliable, loyal, and steadfast. Dependable refers to someone who can be trusted and relied upon to meet their obligations consistently. Consistent denotes a regularity in someone or something's behavior, which makes it predictable. A reliable person is someone who can be counted on to deliver as promised, without fail. Loyal is a quality that refers to someone who is faithful and true to his or her word. Steadfast is a term that denotes a firm and unwavering commitment to something or someone. Together these antonyms paint a picture of someone or something that is trustworthy and committed in his dealings.