sidle UK /ˈsaɪdl/US /ˈsaɪdəl/noun 3verb 2forms 3 noun3 •An act of sidling. •A sideways movement. •A furtive advance.Listener up there! Here you … what have you to confide in me? / Look in my face while I snuff the sidle of evening, / Talk honestly, for no one else hears you, and I stay only a minute longer. — 1855 verb2 •To (cause something to) move sideways.You could drive a band of hosses up the steepest kind of hill but nobody that I ever knowed could drive a bunch straight down (that goes with cows, too)—they'd sidle it every time. — 2011 •In the intransitive sense often followed by up: to (cause something to) advance in a coy, furtive, or unobtrusive manner.There was one little prim old lady, of very smiling and good-humoured appearance, who came sidling up to me from the end of a long passage, [...] — 1842 formssidled · sidling · sidles