Abbott-Smith Manual Greek Lexicon
τρίστεγος (G5152)
1 **† 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.).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain