sensus communis

Literally, “common (i.e., universal, generally shared) sense”. In the philosophical sense, a calque of Ancient Greek κοινὴ ἔννοια (koinḕ énnoia), κοινὴ αἴσθησις (koinḕ aísthēsis), chiefly in Aristotle.

sēnsus commūnis m sg (genitive sēnsūs commūnis); fourth declension

1. tact, manners, discretion
   • c. 65 CE, Seneca the Younger, Epistulae morales ad Lucilium 17.105.4:

     Odium aut est ex offensa: hoc vitabis neminem lacessendo; aut gratuitum: a quo te sensus communis tuebitur.

     Hatred is either the result of an offence—and you shall avoid this by never provoking anyone—or else it is gratuitous, in which case tact will protect you from it.

   • c. 100 CE – c. 130 CE, Juvenal, Satires 3.8.71–74:

     rarus enim ferme sensus communis in illa / fortuna.

     For manners are typically rare in people of that sort.

2. (Medieval Latin, philosophy) the basic faculty of human perception and discrimination between different qualities, shared by all the specific senses and preceding rational judgement

Fourth-declension noun with a third-declension adjective, singular only.

• → English: common sense (calque)
• → French: sens commun (calque)

• “sensus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “communis” on page 370/2 of the Oxford Latin Dictionary (1st ed., 1968–82): “sensus ~is, feeling for others in the same community”
• “sensus communis”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.