disc▪ For ClassAr, Lane vii 1885 specifies the meaning of vb. VI as ‘(to labour, strive, struggle, contend or conflict with each other, to prevail, overcome, gain the mastery, or effect an object:) to contend together, smiting each other, syn. taḍāraba ’. This suggests that the meaning is based on the notion of ‘strength, power, force, effort’, treated under ↗marāsaẗ, as, lit., *‘to apply force against one another’.
▪ But couldn’t it also be related to the notion of ‘getting stuck’ and ‘rubbing’ o.s. against s.th./s.o., as represented by the ClassAr vb. I †marisa ‘to fall from the pulley (a rope) and get stuck fast’? For this complex, cf. ↗marasaẗ ‘rope’.