embezzle - To secretly take money that is in your care or that belongs to an organization or business you work for

The accountant was convincted of having embezzled money from the company, people were surprised that he had been doing it for 10 years before it was discovered.
senile - Used to describe behavior, mental states, or conditions associated with aging, especially when a person becomes forgetful or confused.

The elderly man showed symptoms of becoming senile, like forgetting where he put his keys, but with support, he managed to live independently for a while.