senescent

Adjective

senescent (comparative more senescent, superlative most senescent)

1. Growing old; decaying with the lapse of time.
   • And now, as the night was senescent / ⁠And star-dials pointed to morn— / ⁠As the star-dials hinted of morn— / At the end of our path a liquescent / ⁠And nebulous lustre was born1859, Edgar Allan Poe, “Ulalume”, in The Works of the Late Edgar Allan Poe, volume 2
   • The history of philosophic opinion itself in interpreted by Dr. Hall in terms of a similar development, in which immature adolescent systems, staid senescent and blasé philosophies have appeared and appealed to their public in direct relation to the status of the culture-periods in which they found...1905 March, Joseph Jastrow, “The Natural History of Adolescence”, in Popular Science Monthly, volume 66
2. Characteristic of old age.
3. That ceases to divide.
   • When such lines and forms of organic development prevail, the individual, as the cell of the body, becomes soon senescent, drifting inevitably into age, decay, and death.1919, Boris Sidis, The Source and Aim of Human Progress