to be in one's dotage впасть в де́тство
• Declining state
• Excessive fondness
• Extreme affection
• Faltering condition
• Foolish affection
• Mental decline
• Second childhood
• Second childhood, perhaps
• Senility
• Senility state
• Senior years
• Spoiling
• Waning years
• Mental infirmity as a consequence of old age
• Sometimes shown by foolish infatuations
to be in one's dotage, to sink into dotage - впасть в детство
1. старческое слабоумие
to be in one's ~, to sink into ~ - впасть в детство
2. обожание; слепая любовь
старческое слабоумие.