a. free, without charge; costing nothing
The company offered to give one package gratis to every purchaser of one of their products.
Sentence in Classic:
He goes to the spectacles which God furnishes gratis; he gazes at the sky, space, the stars, flowers, children, the humanity among which he is suffering, the creation amid which he beams.
Les Misérables (V3) By Victor Hugo Context
You cheat the people, you make a contract with the government, and you do the government out of a hundred thousand, supplying it with rotten cloth; and when you give fifteen yards away gratis, you expect a reward besides.
The Inspector-General By Nicolay Gogol Context