The Quran

مَن كانَ يُريدُ العِزَّةَ فَلِلَّهِ العِزَّةُ جَميعًا ۚ إِلَيهِ يَصعَدُ الكَلِمُ الطَّيِّبُ وَالعَمَلُ الصّالِحُ يَرفَعُهُ ۚ وَالَّذينَ يَمكُرونَ السَّيِّئَاتِ لَهُم عَذابٌ شَديدٌ ۖ وَمَكرُ أُولٰئِكَ هُوَ يَبورُ

Muhammad Asad

He who desires might and glory [ought to know that] all might and glory belong to God [alone]. Unto Him ascend all good words, and the righteous deed does He exalt. But as for those who cunningly devise evil deeds - suffering severe awaits them; and all their devising is bound to come to nought.¹

It appears that in this context - as in the first paragraph of 10:21 or in 34:33 - both the noun makr (lit., "a scheme", or "scheming" or "plotting") and the verb yamkurun (lit., "they scheme" or "plot") have the connotation of "devising false [or "fallacious"] arguments" against something that is true. Since the preceding passages refer to God's creativeness and, in particular, to His power to create life and resurrect the dead (verse 9), the "evil deeds" spoken of above are, presumably, specious arguments meant to "disprove" the announcement of resurrection.