senile

形容词 senile:

1. mentally or physically infirm with age
   同义词：doddering, doddery, gaga

1. He may belong to senile residents who stray from home.
   他可能是那种离家迷失在外的昏聩老年人。
2. He keeps forgetting things: I think he's getting senile.
   他总忘事，我看他是老了。