English

Noun

second childhood ‎(plural second childhoods)

1. (idiomatic) The period or state of cognitive decline of an elderly person, characterized by childlike judgment and behavior.
   • 1549, Hugh Latimer, The seconde [seventh] sermon of Maister Hughe Latimer which he preached before the Kynges Maiestie in his graces palayce at Westminster, ye xv. day of Marche [-xix daye of Apryll], M.ccccc.xlix:

     King David being in his childhood, an old man, in his second childhood, for all old men are twice children, as the proverb is, Senex bis puer.

   • 1846, Charles Dickens, Dombey and Son, ch. 52:

     "You think I'm in my second childhood, I know!" croaked the old woman.

   • 1951, "Second Prime," Time, 16 Jul.:

     Old age is not always second childhood, says he. "There is often, instead, a second prime."

2. (idiomatic) A childlike state in any adult, resulting from mental illness, trauma, or other conditions.
   • 1838, Edgar Allan Poe, The Narrative of Arthur Gordon Pym, ch. 11:

     Although at the commencement of the voyage I had been in bad health, and was at all times of a delicate constitution, I suffered less than any of us, being much less reduced in frame, and retaining my powers of mind in a surprising degree, while the rest were completely prostrated in intellect, and seemed to be brought to a species of second childhood, generally simpering in their expressions, with idiotic smiles, and uttering the most absurd platitudes.

   • 1891, James M. Barrie, The Little Minister, ch. 13:

     But take care of yourself; a man's second childhood begins when a woman gets hold of him.

Synonyms

• (cognitive decline of an elderly person): dotage, senile dementia, senility
• (childlike state in any adult): dementia