Ἑρμῄδιον
From LSJ
ὃν οὐ τύπτει λόγος οὐδὲ ῥάβδος → if words don't get through, neither a beating will | if the carrot doesn't work, the stick will not work either | whom words do not strike, neither does the rod
English (LSJ)
τό, Dim. of Ἑρμῆς, Ar.Pax924: as term of endearment, ὦρμῄδιον ib.382. (-ίδιον codd. Ar.)