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.

noun

asepticism , blandness , colorlessness , drabness , dreariness , dryness , flatness , flavorlessness , insipidity , insipidness , jejuneness , sterileness , sterility , stodginess , vapidity , vapidness , weariness