Heartless is a term that is an adjective describing a person, or thing that has no feeling, and that is usually unkind, or not sympathetic to someone or something in need of sympathy. A heartless person is not your ideal romantic, and in fact probably live without being in too many relationships until they actually have a change in heart. The term heartless was first used in the 14th century, and was first used to describe people who had cruel minds, and thoughtless actions. A heartless person is the opposite of a person who puts extreme care into everything they do. Heartless is synonymous with the words cruel, hard-hearted, insensitive, savage and even ruthless. Those who are heartless may be so because of a lack of love provided to them during their upbringings, or because of a ended relationship that scarred their outlook on life. Whatever the cause, it may be wise to be careful when entering into a relationship with someone who doesn't seem to care about much of anything.