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mar m. & f. (Noun) "sea"
12th cent. From Latin mare 'id.' From Proto-Italic *mari- "sea." From Proto-Indo-European *mor-i̯- "sea," but also "lake."
Typically masculine except in poetry, among seafarers, and in other limited environments. The feminine form is a secondary development, however. The word is the origin of the surnames Mares, del Mar, de la Mar, and Delmares.
Asturian mar, Portuguese mar, Galician mar, Catalan mar, French mer, Italian mare, amari, Romanian mare, Sardinianmare
Gaulish Mori-ni (name) "(people) of the sea," Old Irish muir "sea," Welsh mor 'id.,' Old Breton mor 'id.,' Old Cornish mor 'id.'
Gothic mari-saihws "sea," Old Norse marr 'id.,' Old High German mari 'id.,' Old English mere 'id.,' (English mer, first element in mermaid)
Old Church Slavonic morje "sea," Russian móre 'id.,' Czech moře 'id.,' Slovene morję̑ 'id.,' Old Prussian mary 'id.,' Lithuanian mãrės 'id.'
Ossetic mal "stagnant water"

La mar de tonto "Absolutely stupid." From the use of the feminine as a colloquial intensifier (Butt & Benjamin 2004).