Soupçon

un soupçon = a suspicion; a little bit, a trace of (pronounced soop - son)

E.g.
J'ai des soupçons = I have suspicions
Veux-tu un soupçon de vin ? = Would you like a drop of wine?

soupçonner quelqu'un de quelquechose = to suspect someone of something
Je le soupçonne de fumer en cachette = I suspect he secretely smokes