Lacking vitality, energy, or animation. The party was lifeless without any music or dancing.
Devoid of living things; barren or uninhabited. The desert appeared lifeless under the scorching sun.
Lacking the qualities that make something interesting or appealing. The painting was criticized for its lifeless colors and lack of depth.
Not alive; dead or apparently lacking any signs of life. The paramedics arrived too late; the victim was already lifeless.