Wiktionary
acte gratuit
n. An impulsive act lacking motive.
Usage examples of "acte gratuit".
Blake Wells decided not to kill himself by overdosing on his mother's barbiturates when he was down by Harvard, Princeton, Yale in a single hellish mail but accepted by the University of Michigan (where he'd excel, win and fall seriously in love), instead, as an acte gratuit, he sent one longstemmed yellow roses anonymously to his rival Evangeline who'd recently won a Buffalo Evening News-sponsored high school essay contest in which Blake himself had placed fifth.