having no energy and enthusiasm and unwilling to do anything needing effort. He's seemed listless and a little depressed ever since he got his exam results.

​without energy or enthusiasm. He sat listlessly in the armchair. Join us. Join our community to access the latest language learning and assessment tips ...

characterized by lack of interest, energy, or spirit; a listless melancholy attitude; listlessly adverb; listlessness noun.

There is one meaning in OED's entry for the adverb listlessly. See 'Meaning & use' for definition, usage, and quotation evidence.

To be listless is to be lethargic, low spirited, and limp. If a fever has made you feel listless, you might also feel like you are melting into the sofa.

Someone who is listless has no energy or enthusiasm. He was listless and pale and wouldn't eat much. Synonyms: languid, sluggish, lifeless, lethargic.

adjective. having or showing little or no interest in anything; languid; spiritless; indifferent: a listless mood; a listless handshake.

Definitions of listlessly adverb in a listless manner “they shook hands rather listlessly” Cite this entry Style: MLA MLA APA Chicago

Synonyms for LISTLESSLY: wearily, lazily, languidly, casually, indolently, tiredly, desultorily, sluggishly; Antonyms of LISTLESSLY: intently, resolutely, ...