noun
mental infirmity as a consequence of old age; sometimes shown by foolish infatuations
• Hypernyms: ↑old age, ↑years, ↑age, ↑eld, ↑geezerhood
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noun [noncount]
: a time when an old person whose mind is failing begins to behave like a child again
an old man going through his second childhood
Useful english dictionary. 2012.