"And they plotted a mighty plot," meaning great, which is polytheism (shirk).
Muhammad said: It is said that makr kabir (great plot) and kubbar (mighty plot) are in the same meaning. Interpretation of Surah Nuh from verse (23-27).
﴿ومكروا مكرا كبارًا﴾ عَظِيمًا وَهُوَ الشِّرْكُ.
قَالَ محمدٌ: يُقَالُ: مكرٌ كبيرٌ وكُبّارٌ فِي معنى وَاحِد. تَفْسِير سُورَة نوح من آيَة (٢٣ - ٢٧)
