Is it ensure, insure, or assure?
1727, "adhesive," from stick (v.). An Old English word for this was clibbor. First recorded 1864 in the sense of "sentimental;" 1915 with the meaning "difficult." Of weather, "hot and humid," from 1895. Sticky wicket is 1952, from British slang, in reference to cricket.
To defend and support: If his own family won't, who will stick up for him? (1837+)