προπορεία
From LSJ
βορβόρῳ δ' ὕδωρ λαμπρὸν μιαίνων οὔποθ' εὑρήσεις ποτόν → once limpid waters are stained with mud, you'll never find a drink
English (LSJ)
ἡ,
A those who go in front, advanced guard, Plb.9.5.8 (pl.).
German (Pape)
[Seite 741] ἡ, das Voraus- od. Vorangehen, Sp.; auch concret, die Vorangehenden, der Vortrab, Pol. 9, 5, 8.