Henry George Liddell, Robert Scott, A Greek-English Lexicon

A.thrice-cloven, “αἰχμὴ τ.” the trident, Opp.H.5.377.

II. as Subst., τρίγλυφος , ἡ, in Doric architecture, the triglyph, a three-grooved tablet placed at equal distances along the frieze; it seems orig. to have been the end of the beam (the spaces between being at first open and then called ὀπαί, afterwards filled up and called μετόπαι）“, παστάδων ὑπὲρ τέραμνα Δωρικάς τε τριγλύφους” E.Or.1372 (lyr.); “πασσαλεῦσαι κρᾶτα τριγλύφοις” Id.Ba.1214; γεῖσα τριγλύφων (cj. Blomf. for γ᾽ ἔσω) the cornice of (i. e. above) the triglyphs, Id.IT113; “σὺν τῇ τ.” IG22.1668.30; “τριγλύφων γωνιηιᾶν” SIG 247 ii61 (Delph., iv B. C.):—pl. τρίγλυφα, τά, Diph.61.2.