means A portion or share of something expressed as a fraction of one hundred.

from From the Latin per centum, 'by the hundred' — the merchant's and tax-collector's phrase for reckoning per each hundred units. It came into English through Italian commercial math, where bankers and accountants of the late medieval and Renaissance trading world tallied interest and profit in hundredths. 'Percent' arrived first; 'percentage' followed as the noun for the amount itself, with the suffix '-age' (the same one in 'mileage' and 'postage') marking 'an amount measured by.'