μετεωρόρριζος
From LSJ
οὐκ ἂν λάβοις παρὰ τοῦ μὴ ἔχοντος → you can't take from one who doesn't have, you can't squeeze blood out of a turnip, you can't get blood out of a turnip, you can't get blood from a stone, you can't get blood out of a stone
Greek (Liddell-Scott)
μετεωρόρριζος: -ον, ὁ ἔχων τὰς ῥίζας κατὰ τὴν ἐπιφάνειαν, Θεοφρ. π. Φυτ. Ἱστ. 4. 2, 4.
