My late father referred to a friend who had developed 'Old Timer's Disease' for Alzheimer's Disease.

Another mondegreen, in Portuguese, was heard by a female friend of mine after the 1974 revolution in Portugal in which the Communist party had become prominent. My friend was complimented at a dinner party for being very beautiful, like a 'protaganista' (a movie star) but which she heard as, and was accordingly insulted by, the phrase 'puta comunista' (a Communist whore).