ppl. a. (UN-1 10.)

1

1818.  Shelley, Julian, 538. One unsustaining reed. Ibid. (1820), Sensit. Pl., 78. The light winds which from unsustaining wings Shed the music of many murmurings.

2

1880.  Miss Bird, Japan, II. 267. Rice and eggs were … unsustaining food.

3