felsenfest

== German == === Etymology === Felsen (“rock”) +‎ fest (“fixed, immutable”). === Pronunciation === === Adjective === felsenfest (strong nominative masculine singular felsenfester, not comparable) adamant; rock solid ==== Declension ==== === Further reading === “felsenfest” in Duden online “felsenfest”, in Digitales Wörterbuch der deutschen Sprache‎[1] (in German)