O.E. mara (adj.) "greater, more," used as a comp. of micel "great" (see mickle), from P.Gmc. *maizon (cf. O.S. mera, O.N. meiri, O.Fris. mara, M.Du. mere, O.H.G. mero, Ger. mehr), from PIE *meis (cf. Avestan mazja "greater," O.Ir. mor "great," Gk. -moros "great," Oscan mais "more"). O.E. used related ma "more" as adv., n., from P.Gmc. *mais; this became M.E. mo, but more in this sense began to predominate in later M.E.
[mawr, mohr] 