le sillage
Ce bateau laisse un grand sillage - This boat leaves a big wake.
J'ai vu le sillage d'un avion hier - I saw a plane's (vapor) trail yesterday.
Suivons le sillage de parfum - Let's follow the scent of perfume.
Related: dans le sillage de qqun - in someone's wake (lit and fig); marcher dans le sillage de qqun - to follow in someone's footsteps
(click the little red + white graphic below to hear the Mot du jour pronounced)
Pronunciation: [see yazh]