δυσμάχανος

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

Source

Spanish (DGE)

v. δυσμήχανος.

Russian (Dvoretsky)

δυσμάχᾰνος: (ᾱχ) дор. = δυσμήχανος.