"You canker blossom!" 3 Shakespearean Insults
"to fasten (a vessel) by a cable," late 15c., probably related to Old English mærels "mooring rope," via unrecorded *mærian "to moor," or possibly borrowed from Middle Low German moren or Middle Dutch maren "to moor," from West Germanic *mairojan. Related: Moored, mooring. French amarrer is from Dutch.
"waste ground," Old English mor "morass, swamp," from Proto-Germanic *mora- (cf. Old Saxon, Middle Dutch, Dutch meer "swamp," Old High German muor "swamp," also "sea," German Moor "moor," Old Norse mörr "moorland," marr "sea"), perhaps related to mere (n.), or from root *mer- "to die," hence "dead land."
The basic sense in place names is 'marsh', a kind of low-lying wetland possibly regarded as less fertile than mersc 'marsh.' The development of the senses 'dry heathland, barren upland' is not fully accounted for but may be due to the idea of infertility. [Cambridge Dictionary of English Place-Names]
"North African, Berber," late 14c., from Old French More, from Medieval Latin Morus, from Latin Maurus "inhabitant of Mauritania" (northwest Africa, a region now corresponding to northern Algeria and Morocco), from Greek Mauros, perhaps a native name, or else cognate with mauros "black" (but this adjective only appears in late Greek and may as well be from the people's name as the reverse). Being a dark people in relation to Europeans, their name in the Middle Ages was a synonym for "Negro;" later (16c.-17c.) used indiscriminately of Muslims (Persians, Arabs, etc.) but especially those in India.