Gratis

наречие [латинский язык] бесплатно, даром Синоним(ы): free of charge

Большой англо-русский словарь

Gratis

adverb or adjective Etymology: Middle English, from Latin gratiis, gratis, from ablative plural of gratia favor — more at grace without charge or recompense; free Example: the food was supplied gratis

Merriam-Webster's Collegiate Dictionary