Webster's Revised Unabridged Dictionary · 1913

Cacoethes

Cacoethes , noun

[Latin, from Greek {not transcribed} of ill habits, {not transcribed} an ill habit; kako`s bad + {not transcribed} habit]

1.
A bad custom or habit; an insatiable desire; as, cacoethes scribendi, “The itch for writing”. — Addison
2.
(Medicine) A bad quality or disposition in a disease; an incurable ulcer.