savoir faire

noun

1. knowledge of just what to do in any situation; tact.

noun

1. the ability to do the right thing in any situation

n.“instinctive knowledge of the right course of action in any circumstance,” 1815, from French, literally “to know (how) to do,” from savoir “to know” (from Latin sapere; see sapient) + faire (from Latin facere; see factitious). French also has savoir-vivre “ability in good society; knowledge of customs in the world.” Ease and dexterity in social and practical affairs: “Peter is a friendly person, but he lacks the savoir faire required for a successful career in the foreign service.” From French, meaning “to know how to act.”