τραπέζιον
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
English (LSJ)
τό, Dim. of τράπεζα,
A small table, Phylarch.44 J.: table of a money-changer, Lys.Fr.50. II Geom., trapezium, Arist. Pr.911a7, Archim.Sph.Cyl.1.10, al., D.P.175, Str.2.5.33.
