ἐχεμυθία
From LSJ
τίς δ' οἶδεν εἰ τὸ ζῆν μέν ἐστι κατθανεῖν, τὸ κατθανεῖν δὲ ζῆν κάτω νομίζεται → who knows if life is death, and if in the underworld death is considered life
English (LSJ)
ἡ,
A silence, reserve, ἡ Πυθαγόρειος ἐ. Plu.Num.8, cf. 2.728d, Ph.2.267 (v.l. -θυμία), Alciphr.3.55, Ath.7.308d, Iamb.VP 6.32, etc.