perspicacity

The story

1. Latin · derived fromperspicācitās“sharpsightedness, discrimination”
2. Middle French · derived fromperspicacité
3. English todayperspicacity

From Middle French perspicacité (whence -acity) or directly from Latin perspicācitās (“sharpsightedness, discrimination”), from perspicāx (“sharp-sighted”), from perspicio, from per- + specio, "see through (something)".