All 4 Uses

senile
in
Slaughterhouse-Five
(Auto-generated)

Billy has gone to sleep a senile widower and awakened on his wedding day.†
Chpt 2 *

senile = mental weakness caused by old age; or describing a medical condition as caused by old age
The orchestration of the moment was this: Barbara was only twenty-one years old, but she thought her father was senile, even though he was only forty-six-senile because of damage to his brain in the airplane crash.†
Chpt 2
The orchestration of the moment was this: Barbara was only twenty-one years old, but she thought her father was senile, even though he was only forty-six-senile because of damage to his brain in the airplane crash.†
Chpt 2
And Billy, meanwhile, was trying to hang onto his dignity, to persuade Barbara and everybody else that he was far from senile, that, on the contrary, he was devoting himself to a calling much higher than mere business.†
Chpt 2

Definitions:

(1) (senile)
weakness from old age (especially mental weakness); or describing a medical condition as caused by old age
(2) (meaning too rare to warrant focus)