Source : Webster's Revised Unabridged Dictionary (1913)

Soupcon \Soup`[,c]on"\, n. [F.]
   A suspicion; a suggestion; hence, a very small portion; a
   taste; as, coffee with a soup[,c]on of brandy; a soup[,c]on
   of coquetry.

Source : WordNet®

soupcon
     n : a slight but appreciable addition; "this dish could use a
         touch of garlic" [syn: {touch}, {hint}, {tinge}, {mite},
         {pinch}, {jot}, {speck}]