plain Jane

Noun

 * 1)  A young woman or girl of average or unremarkable appearance.
 * 2)  Something basic and ordinary.
 * 1)  Something basic and ordinary.

Translations

 * German: graue Maus, unscheinbares Mädchen, farbloses junges Mädchen
 * Polish: szara mysz
 * Russian: се́рая мышь