The Collaborative International Dictionary of English v.0.48:

Scintilla \Scin*til"la\, n. [L.]
   A spark; the least particle; an iota; a tittle. --R. North.
   [1913 Webster]

WordNet (r) 3.0 (2006):

scintilla
    n 1: a tiny or scarcely detectable amount [syn: shred,
         scintilla, whit, iota, tittle, smidgen,
         smidgeon, smidgin, smidge]
    2: a sparkling glittering particle

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "scintilla":
   blink, blinking, cast, coruscation, dash, firefly, gleam, glimmer,
   glimmering, glisten, glister, glitter, glittering, glowworm, hint,
   idea, intimation, lick, look, scintillation, shade, shadow,
   shimmer, shimmering, sip, smack, smattering, smell, soupcon,
   spangle, spark, sparkle, sprinkling, stroboscopic light,
   suggestion, sup, suspicion, taste, thought, tincture, tinge,
   tinsel, touch, trace, twinkle, twinkling