LSJ
ατος, τό, supporting beam, IG 2.1054.68, 11 (2).287 A 84 (Delos, iii BC); also δ. χαλκᾶ ib. 2.652A 25.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
τό, Stütze, Phot. lex. v. κνημία.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)