LSJ
ές, formed like a Λ ; ὀστοῦν λ. the os hyoïdes, Gal. 18(2).957, Orib. 25.8.1; ῥαφή the suture in the skull between the occiput and sinciput, Gal. UP 9.5, Ruf. Onom. 133; διάγραμμα Theol.Ar. 3. (λαμβδ- is freq. written in codd. and is v.l. in Gal. UP l.c., Orib. l.c., but λαβδ- Poll. 2.37, 4.133.)
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ές, dem Buchstaben Λ ähnlich, Sp., bes. Medic.; Poll. 2.37, 4.133.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)