Hapax is a compact adverb with outsized theological weight. In ordinary usage it simply means 'one time' — Paul was shipwrecked, the Philippians sent aid 'once and again' (Phil 4:16). But in Hebrews it becomes a term of art for the unrepeatable finality of Christ's sacrifice: the high priest entered the Most Holy Place 'once a year' (Heb 9:7), but Christ entered 'once for all' (Heb 9:12, 10:10), rendering further offerings unnecessary. Jude 3 uses it for the faith 'once for all delivered to the saints.' The translations converge simply: Spanish 'una vez,' French 'une fois,' German 'einmal' — but the theological density of those two syllables in Hebrews far exceeds their surface simplicity.