flint
From LSJ
English > Greek (Woodhouse)
substantive
Use stone.
flint for striking a spark: use P. and V. πυρεῖα, τά (which were pieces of wood, not stone) (Plato, Republic 435A; Soph., Philoctetes 36).
rubbing flint against flint, I produced with labour a dim spark: V. ἀλλ' ἐν πέτροισι πέτρον ἐκτρίβων μόλις ἔφην' ἄφαντον φῶς (Soph., Philoctetes 296).