Wiktionary
n. an Islamic prayer whereby a phrase or expression of praise is repeated continually
Wikipedia
Dhikr (also Zikr, Zekr, and variants; ( ḏikr; plural aḏkār, meaning " remembrance") is the name of devotional acts in Islam in which short phrases or prayers are repeatedly recited silently within the mind or aloud. Rarely, it is counted on a string of beads or a set of prayer beads ( Misbaha ), comparable to the rosary of Catholic tradition. A person who recites the rosary is called a ḏākir (ذاكر). Most Sufis follow this practice of Dhikr although the word being recited varies. Tasbih is a form of dhikr that involves the repetitive utterances of short sentences glorifying God. The content of the prayers includes the names of God, or a duʿāʾ (prayer of supplication) taken from the hadith or the Quran.