Willard Espy writes in his 1980 book Another Almanac of Words at Play (Feb 12): "Anguish Languish, popularized by the late Howard L. Chance, is a form of punning in which words overlap to give an impression of other words, as clouds assume forms according to the fancy of the observer."
Eckler, A. Ross
Word Ways: Vol. 30
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol30/iss4/10