Matra (take)

The matra is a coarse blanket of wool or cotton that is placed on top of the sweatshirt or replaces it. It is placed on the back of the horse when saddling it and above the same goes the ride. The word matra explains the existence of another word: matrero since it was called gaucho matrero or matrero to the gaucho who evaded the law imposed by rivadavianos in the 1820 and later emphasized by the mitristas since the 1860 (for example gauchos called "matreros" they eschewed to be conchabados or to be reduced to "peones rurales" to the control of a estanciero "patron"), in such case such gauchos frequently, declared "out of the law" had no other option than a life of trashumancia riding his horse and spending the night using the matras as if they were blankets.

wiki