negligible - So small or unimportant that it can be ignored or doesn't have a noticeable effect; insignificant in amount, size, or impact — too minor to be worth considering.
The difference in price was negligible, so she bought the higher-quality clothing.
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.