obsolescent, a.
(ɒbsəʊˈlɛsənt)
[ad. L. obsolēscent-em, pr. pple. of obsolēscĕre: see obsolesce v.]
1. Becoming obsolete; going out of use or date.
| 1755 Johnson s.v. Hereout, All the words compounded of here and a preposition, except hereafter, are obsolete, or obsolescent. 1863 Kirk Chas. Bold II. 82 The stronghold of obsolescent opinions and decaying sects. 1880 Plumptre Comm. Luke 381 ‘They were instant’. The adjective is almost passing into the list of obsolescent words. 1894 Jos. Wright Appeal Eng. Dial. Dict. 3 In another generation the obsolescent will have become obsolete. |
2. Biol. Gradually disappearing; imperfectly or slightly developed; said of an organ structure, or mark, which was formerly, in the life of the individual or the species, or is still in cognate species, fully developed or well-marked.
| 1846 Dana Zooph. iv. (1848) 80 The Echinopores are other examples of prominent polyps, and obsolescent striæ to the coralla. 1879 G. Allen Colour Sense iii. 26 The Law of Parsimony, whereby all unnecessary organs become gradually obsolescent. 1892 Syd. Soc. Lex., Obsolescent,..applied to such a thing as a tubercle in the lung which is shrinking and becoming the seat of calcareous infiltration. 1897 Allbutt's Syst. Med. II. 11 The fibroid patches..are a form of what is called retrograde or obsolescent tubercles. |
Hence obsoˈlescently adv. (cf. 2 above).
| 1846 Dana Zooph. (1848) 320 Polyps obsolescently tentaculate. |