καιάδας

ου, α, ὁ
A. a pit or underground cavern at Sparta, into which state-prisoners or their corpses were thrown, Th. 1.134, Paus. 4.18.4:—the forms καιάτας and καιέτας are found in Eust. 1478.45:— also καιετός, ὁ, fissure produced by earthquake, Str. 8.5.7: hence Λακεδαίμονα
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project