Main Entry: se·nile

Pronunciation: \ˈsē-ˌnī(-ə)l also ˈse-\

Function: adjective

Etymology: Latin senilis, from sen-, senex old, old man

Date: 1661

1 : of, relating to, exhibiting, or characteristic of old age <senile weakness>; especially : exhibiting a loss of cognitive abilities (as memory) associated with old age
2 : approaching the end of a geological cycle of erosion

— se·nile·ly \-ˌnī(-ə)l-lē\ adverb