worldly life / this world
Feminine noun (originally an adjective meaning 'nearer/lower'). From دَنَا (to be near/low). Called dunyā because it is the 'nearer' life (compared to the ākhirah) and 'lower' in rank.
The etymology reveals the Quranic worldview: this life is both 'near' (temporary, at hand) and 'low' (less valuable than the eternal Hereafter).