δυσκάθαρτος
From LSJ
Kατεσκευάσθη τὸ ἱερὸν τοῦτο ποτήριον ... ἐν ἔτει ,αω'α' → Τhis holy cup was made ... in the year 1801
English (LSJ)
[κᾰ], ον,
A hard to purify, Ph.1.239, al.; hard to purge, πνεύματα Plu.2.991b, cf. Dsc.5.69. II hard to satisfy by purification or atonement, δ. Ἅιδου λιμήν, of the house of the Labdacidae in which murders never ceased, S.Ant. 1284 (lyr.); δαίμων Ar.Pax1250.