senile

As a noun taxonomy

is the science or the technique used to make a classification.

As an adjective senile is

senile.

As adjectives the difference between senile and superannuated

is that senile is senile while superannuated is obsolete, antiquated.

As a verb superannuated is

(superannuate).

As an adjective senile

is senile.

As a noun superannuation is

(usually|uncountable|uk|australia|new zealand) a retirement benefit fund, an accumulation of regular deductions from one′s wage or salary while employed and similar regular contributions from the employer, usually administered by an independent entity; a pension.

As an adjective senile

is senile.

As a noun nicergoline is

an ergot derivative used to treat senile dementia and other disorders with vascular origins.

As adjectives the difference between senile and nonsenile

is that senile is senile while nonsenile is not senile.

As an adjective senile

is senile.

As a noun selegiline is

a drug used for the treatment of early-stage parkinson's disease, depression and senile dementia.

As adjectives the difference between senile and geezery

is that senile is of, or relating to old age while geezery is like a geezer: old and senile.