taetricitas
From LSJ
ξένῳ δὲ σιγᾶν κρεῖττον ἢ κεκραγέναι → it's better for a stranger to keep silence than to shout (Menander)
Latin > English (Lewis & Short)
taetrĭcĭtas: (tētr-), ātis, f. taetricus,
I a grave or serious expression; gravity, seriousness: habitus oris taetricitate decorus, Auct. Pan. ad Pis. 90.
Latin > French (Gaffiot 2016)
tætrĭcĭtās (tetr-), ātis, f. (tætricus), air sombre, sévère : Ps. Sal. Bass. Laus Pisonis 103.