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

A.juice, distd. from χυλός, χυμός, in that ὀπός is prop. vegetable juice, the milky juice which is drawn from a plant by tapping it, “ὀπὸν . . στάζοντα τομῆς . . κάδοις δέχεται” S.Fr.534 (anap.), cf. Thphr. HP9.8.1, etc. ; esp. the acid juice of the fig-tree, used as rennet (τάμισος) for curdling milk, Il.5.902, Emp.33, Hp.Morb.4.52, Menestor ap.Thphr.HP1.2.3, Arist.Mete.384a21,389b10, GA737a14 ; generally, acid juice, Pl.Ti.60b ; “βλέπειν ὀπόν” Ar.Pax1184 : in pl., Antiph.88.4, cj. in Anaxandr.41.59 (anap.); cf. ὀπίας, ὀποειδής,

2. metaph., ὀπὸς ἥβης the juicy freshness of youth, opp. ῥυτίς, AP5.257 (Paul. Sil.).

II. ὀποῦ καρπός, = σιλφίου σπέρμα, Hp. ap. Gal.19.126 ; and so prob. in Ar.Ec.404, Pl.719 ; but ὀπὸς σιλφίου silphium juice, Hp. Acut.23, cf. 37, Acut.(Sp.)48, Thphr.HP6.3.2 ; so ὀπός alone, Gal. 12.90.

III. gravy, Ath.9.402c. (Perh. cf. Lith. sakaĩ (pl.) 'resin', Slav. sok[ucaron] 'sap'.)