νεροσέλινον

From LSJ

ποιητὴς, ὁπόταν ἐν τῷ τρίποδι τῆς Μούσης καθίζηται, τότε οὐκ ἔμφρων ἐστίν → whenever a poet is seated on the Muses' tripod, he is not in his senses

Source

Greek (Liddell-Scott)

νεροσέλινον: τό, ὡς καὶ νῦν, τὸ ἐν ὕδασι φυόμενον ἀγριοσέλινον, Δουκάγγ.