The word tare originates from Arabic طرح ṭarḥ, lit. "thing deducted or rejected". Medieval Arabic tarh was also used meaning "a deduction, a subtraction".

The tare weight is defined in English as the weight of a package that's empty. To get the net weight of goods in a package, you weigh the goods in their package, which is the gross weight, and then discard the tare weight. Catalan tara dates from 1271, French tare 1311, Italian tara 1332, England tare 1380. The word has a record in Spanish around 1400 in the form atara, which helps affirm Arabic ancestry because the leading 'a' in atara represents the Arabic definite article. It is spelled tara in today's Spanish, Italian, German, and Russian.

More Info: en.wikipedia.org