Is it ensure, insure, or assure?
"sinuous and slender," of women or clothes, 1921, from slink + -y (2). Related: Slinkily; slinkiness. As a proprietary name (with capital from S-) for a coil of spring marketed as a toy, 1948, by James Industries Inc., Philadelphia, U.S.A.
To write, esp as a newspaper reporter or otherwise professionally (1864+)