All these words pertain to a lack of spirit or energy. Listless is the least formal of these and the most wide-ranging in application. At its most specific, the word can indicate slow or sluggish movement, at its most general a lack of the vibrance associated with good health or high spirits: He responded to my question with a listless shrug of his shoulders; the listless faces of a family on relief; a class of listless children on a 100-degree day. Most often, the word suggests a general apathy that may well be the result of disease or physical or mental fatigue.

Languid can also indicate a lack of interest or animation that may stem from poor health or fatigue, but it can also (and perhaps more often) indicate an avoidance of physical exertion as a matter of choice or temperament rather than of necessity: drooped in her languid pose on a bench while her friends walked from painting to painting in the exhibition. It can also suggest the affecting of a slow or lazy manner: the languid drawl with which he spoke. In a way that listless cannot, languid can indicate anything that is lacking in force: a languid wind that offered no relief from the heat. Languorous and languid both derive ultimately from the same French root, meaning to languish . Languorous gives a distinct and specific meaning that points to the affecting of an effete or indolent dreaminess: an era of crisis in which many retired to languorous meditation and disengagement.

Lethargic concentrate on the aspect of listless that pertains to sluggish movement, but it is slightly more formal than listless and is considerably more critical or disapproving in tone. The word may, in fact, suggest laziness as the cause of this behaviour: too lethargic to get his homework done on time. Lackadaisical concentrates on a different aspect of listless , the one referring to a lack of vibrance, spirit or energy: reacting to the impassioned speech with a lackadaisical yawn; entrenched bureaucrats who are lackadaisical about proposals to make the system more efficient or humane. It can also refer to whatever is idle, indifferent or empty of value: a lackadaisical attitude towards standards of accuracy and objective scholarship.