not endowed with life; having no life; inanimate

lifeless matter.

destitute of living things

a lifeless planet.

deprived of life; dead

a battlefield strewn with lifeless bodies.

without animation, liveliness, or spirit; dull; colorless; torpid

a lifeless performance of a play.

insensible, as a person who has fainted.

adjective

alive , animate , living , energetic , lively , spirited

adjective

asleep , bare , barren , brute , cold , comatose , dead , deceased , defunct , departed , desert , empty , exanimate , extinct , faint , inanimate , inert , inorganic , insensate , insensible , late , out cold * , sterile , unconscious , uninhabited , waste , blah * , colorless , drab , draggy , flat , hollow , insipid , lackluster , lethargic , listless , lusterless , nothing * , pabulum * , passive , prosaic , prosy , slothful , slow * , sluggish , spent , static , stiff * , torpid , wooden * , zero * , gone , arid , aseptic , dry , earthbound , flavorless , matter-of-fact , pedestrian , spiritless , stodgy , unimaginative , uninspired , adenoidal , amort , apathetic , automatic , bloodless , deal , devitalized , dull , inactive , insentient , mechanical , quiescent , stiff , unresponsive , vapid , wooden