Single-hearted is a term used to describe a person who possesses a focused and unwavering devotion to a particular goal or ideal. Antonyms for single-hearted include multi-faceted, unfocused, disloyal, indecisive, uncommitted, and unfaithful. Someone who is multi-faceted lacks the single-minded focus of a single-hearted individual and may be interested in a variety of different things. Unfocused individuals lack the clarity of purpose that single-hearted people possess. Disloyal and unfaithful individuals lack the unwavering commitment that is characteristic of single-minded people. Indecisive and uncommitted people tend to be hesitant and uncertain, lacking the decisive nature of single-hearted individuals.