διάκοιλος
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)
διάκοιλον, quite hollow, D.S.17.115.
Spanish (DGE)
-ον hueco Σειρῆνες ref. estatuas, D.S.17.115, καυλός Dsc.4.114.
German (Pape)
ganz hohl, Diod. 17.115.
Russian (Dvoretsky)
διάκοιλος: полый, пустотелый (sc. ἀνδριάντες Diod.).
Greek (Liddell-Scott)
διάκοιλος: -ον, ὅλως κοῖλος, Διόδ. 17. 115.