What does "senility" mean?

The bodily and mental deterioration associated with old age: Synonym of senescence.

Senility

Common synonyms include: dotage, second childhood, aboriginality, abulia, advanced age, advanced years.

//səˈnɪlɪti// noun

noun ·Moderate ·College level

Noun

1
The bodily and mental deterioration associated with old age: Synonym of senescence. uncountable
"Near-synonym: second childhood"
2
the state of being senile wordnet
3
The losing of memory and reason due to senescence. uncountable
"He was entering his years of senility and not liking it a bit."
4
mental infirmity as a consequence of old age; sometimes shown by foolish infatuations wordnet
5
An elderly, senile person. archaic, countable
"There was no need for George Playford to talk as if they were doddering senilities."