ein meaning and definition in german

In the vernacular, the diphthong ei- is usually not pronounced in the indefinite article, which gives rise to the informal contractions 'n, 'ne, 'nem, 'ner (dative), and 'nen. (There are no contracted genitive forms.)
Earlier contracted forms which are not in use anymore are eim for einem and eins for eines (as in "eins Mann[e]s", "eins Kind[e]s"). Even older forms are ein for eine (as in ein Frau), einm for einem and einr for einer.