noun
fifty percent; half
Used for proportions, discounts, and statistics. 割 means 'tenth', so 五割 is literally 'five tenths'.
この商品は五割引きです。
This item is 50% off.
参加者の五割が女性だった。
Fifty percent of the participants were women.
半分 is the general word for 'half' of something, while 五割 specifically means 50% and is often used in numerical or statistical contexts.
五十パーセント is the direct loanword equivalent, more common in casual speech; 五割 sounds slightly more formal or traditional.
Compound of 五 (five) and 割 (tenth, proportion). 割 is a traditional Japanese unit for tenths, commonly used in percentages and discounts.