arroba
noun
ar·ro·ba ə-ˈrō-bə 
1
: an old Spanish unit of weight equal to about 25 pounds
2
: an old Portuguese unit of weight equal to about 32 pounds
Word History
Etymology
borrowed from Spanish, borrowed from Arabic al rubʽ "the quarter" (the unit being a quarter of a Spanish quintal), from al "the" + rubʽ "quarter," derivative of a root r-b-ʽ, whence also arbaʽa "four"
First Known Use
1555, in the meaning defined at sense 1