Today's OED antedating: "whatchamacallit"

Whatchamacallit, colloquial, code for an unrecalled word (first use cited 1928): Untitled item by Franklin P. Adams, New York Tribune, November 17, 1915, p 9, col 1: "It is, one might say if one were desperate for a two-line ¶, a what-you-McCall-it shame."