He seemed eternally indestructible as he sat there surrounded by danger, his features molded firmly into that same fierce, regal, just and forbidding countenance which was recognized and revered by every man in the squadron.
The only end in sight was Yossarian’s own, and he might have remained in the hospital until doomsday had it not been for that patriotic Texan with his infundibuliform jowls and his lumpy, rumpleheaded, indestructible smile cracked forever across the front of his face like the brim of a black ten-gallon hat.
The chaplain glanced at the bridge table that served as his desk and saw only the abominable orange-red pear-shaped plum tomato he had obtained that same morning from Colonel Cathcart, still lying on its side where he had forgotten it like an indestructible and incamadine symbol of his own ineptitude.
There are no more uses of "indestructible" in the book.
Show samples from other sources
When the fear takes over, use the only thing more powerful, more indestructible, to fight it: your spirit.
Sabaa Tahir -- An Ember in the Ashes
"Nick, don’t let one good turn make you feel indestructible," Go said.