sudarium
From LSJ
Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
Latin > English (Lewis & Short)
sūdārĭum: ii, n. sudor,
I a cloth for wiping off perspiration, a handkerchief, Cat. 12, 14; 25, 7; Mart. 11, 39, 3; Petr. 67: sudario candido tergere frontem, Quint. 6, 3, 60; 11, 3, 148; Suet. Ner. 25; 48; 51; Val. Max. 9, 12, 7; App. Mag. p. 309, 28.
Latin > French (Gaffiot 2016)
sūdārĭum,¹³ ĭī, n. (sudo), mouchoir : Catul. 12, 14 ; Quint. 6, 3, 60 || suaire : Eccl.