Yossarian, we live in an age of distrust and deteriorating spiritual values.
Or was the whole fantastic episode merely the figment of a diseased imagination, his own, of a deteriorating mind, a rotting brain?
The men are unhappy and morale is beginning to deteriorate.
Morale was deteriorating and it was all Yossarian’s fault.
He was forced to admit that the hospitals had altered steadily for the worse as the war continued and one moved closer to the battlefront, the deterioration in the quality of the guests becoming most marked within the combat zone itself where the effects of booming wartime conditions were apt to make themselves conspicuous immediately.
There are no more uses of "deteriorate" in the book.
Show samples from other sources
The situation could quickly deteriorate.
Writing, at its best, is a lonely life. Organizations for writers palliate the writer’s loneliness, but I doubt if they improve his writing. He grows in public stature as he sheds his loneliness and often his work deteriorates.