年

lost twenty years; first two decades of economic stagnation in Japan that began ca. 1991

jubilee; semicentennial

corporate pension plan

Colloquial

divorce of a couple who have been married for a long time (brought on by retirement of the husband)

annually; year by year

Branchinella kugenumaensis (species of fairy shrimp)

Law

adult guardian; guardian of adult

waiting for one hundred years for the waters of the Yellow River to clear; waiting in vain for an unlikely event; waiting for pigs to fly; when the sky falls, we shall catch larks

working youth

children's literature; juvenile literature

Medicine

early-onset dementia; presenile dementia

half a year

have a happy New Year

Medicine

susceptible age (for a disease, condition, etc.); common age

legislators' pension (and retirement benefits)

the 1900s

gerontology

Botany

annual herb

Colloquial

the 2010s

Slang

same age

bad year (for fruit); off year

low pollen year

man of perennial youth; man who never loses his youthful vigor

Law

juvenile delinquent under the age of fourteen; minor in trouble with the law

youthful ardor; rash impulse of an inexperienced youth