Is it ensure, insure, or assure?
familiar form of masc. proper name Tobias, in various colloquial usages, e.g. "jug" (1840), "drinking mug in the form of a stout old man;" as a type of collar (1882) it refers to that worn by the dog Toby in the 19c. Punch and Judy shows. Also in Toby show (by 1942, American English) "comedy act based on the stock character of a boisterous, blundering yokel."