he sent down / he revealed
Form IV verb (أَفْعَلَ). Past: أَنْزَلَ, Present: يُنْزِلُ. Also Form II: نَزَّلَ (sent down gradually). Form I: نَزَلَ (descended). Related: تَنْزِيلٌ (revelation).
Laylat al-Qadr (Night of Decree) is the night the Quran began to be revealed. Muslims seek it in the last ten nights of Ramadan.