listless

Synonyms: absent abstracted apathetic blah bored careless dormant dreamy drowsy dull easygoing energyless enervated faint heavy heedless impassive inanimate inattentive indifferent indolent inert insouciant lackadaisical lagging laid-back languid languishing languorous leaden lethargic lifeless limp lukewarm lymphatic mopish neutral out of it passive phlegmatic slack sleepy slow sluggish stupid supine thoughtless torpid uninterested vacant

Antonyms: active alert attentive energetic lively untired