An Etymological Dictionary of the German Language/Annotated/jäh

by Friedrich Kluge

jäh, gähe, adjective, ‘steep, precipitous, hasty,’ from Middle High German gœhe (also gâch), Old High German gâhi, adjective, ‘quick, suddenly, impetuous’; a specifically German word (with a dialectic initial j for g as in jappen; compare also jähnen with gähnen). From this French gai, ‘gay,’ is borrowed. Its connection. with gehen, gegangen (see Gang), is impossible. Gaudieb is, on the other hand, allied to it.