Italian soave < Latin suavis 'charming, pleasant, agreeable, attractive', cf. English suave. French svelte is from Italian svelto, past passive participle of svellere 'to stretch out' < Vulgar Latin *exvello < Latin evello, evellere, 'to tear, pluck out; eradicate'. Italian sospire < Latin susspiro, susspire, 'to sigh; heave a sigh'. (It reminded me of Dario Argento's horror movie Suspiria.)

Ceci n'est pas un seing.