WordNet (r) 3.0 (2006):

svelte
    adj 1: showing a high degree of refinement and the assurance
           that comes from wide social experience; "his polished
           manner"; "maintained an urbane tone in his letters" [syn:
           polished, refined, svelte, urbane]
    2: moving and bending with ease [syn: lissome, lissom,
       lithe, lithesome, slender, supple, svelte,
       sylphlike]
    3: being of delicate or slender build; "she was slender as a
       willow shoot is slender"- Frank Norris; "a slim girl with
       straight blonde hair"; "watched her slight figure cross the
       street" [syn: slender, slight, slim, svelte]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "svelte":
   airy, attenuate, attenuated, boyish, delicate, diaphanous, diluted,
   ethereal, fine, fine-drawn, finespun, flimsy, frail, gauzy,
   girlish, gossamer, gracile, insubstantial, lacy, light, misty,
   papery, rare, rarefied, slender, slenderish, slight, slight-made,
   slim, slimmish, slinky, small, subtle, sylphlike, tenuous, thin,
   thin-bodied, thin-set, thin-spun, thinnish, threadlike, vague,
   wasp-waisted, watered, watered-down, watery, weak, willowy,
   wiredrawn, wispy