μάστις
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
English (LSJ)
ιος, ἡ, Ion. for foreg., dat.
A μάστῑ Il.23.500; acc. μάστιν Od.15.182, AP6.234 (Eryc.):—also μαστίδες· ἀκίδες ἢ ἀγκύλαι, Hsch.