obsoˈlescing, ppl. a.
[f. obsolesce v. + -ing2.]
That is becoming obsolete.
| 1916 E. V. Lucas Cloud & Silver 71 The Mayor..still clung to the steadily obsolescing topper. 1953 Sun (Baltimore) 23 Oct. 2/7 This sort of conversion [of gun turrets] is, in fact, under way, with other heavy ‘obsolescing’ types. |