Lexical Definition

‎τρίστεγον‎ trístegon (tris'-teg-on) third story ^G:N-N
neuter of a compound of ‎τρεῖς‎ and ‎στέγη‎ as noun

third loft.

• a third roof (story)

Abbott-Smith

**† τρίστεγος, -ον (τρεῖς, στέγη) [in Sm.: Ge 6:17(16), Ez 42:6 * ;]
of three stories: τὸ τ. (sc. ὄκημα),
the third story, Ac 20:9 (Dion., FlJ, al.).†

Abbott-Smith References

Liddell-Scott-Jones

τρίστεγος-στεγος, ον,

of or with three stories, [Refs 2nd c.BC+]

__II τὸ τ. (i.e. οἴκημα) the third story, [NT]:—also τριστέγη, ἡ, [Refs 2nd c.AD+]

_{LSJ Scripture Refs: Acts.20.9}