wahnsinnig

Etymology
Coined in the 15th century after the model of wahnwitzig which uses as its first part the word wahn, which came from "missing, empty", which came from. Not cognate with Wahn. Cognate with English wane.

Adjective

 * 1) mad, insane
 * 2) incredible, unbelievable
 * 1) incredible, unbelievable

Adverb

 * 1) incredibly, awfully