/ ˈgrætɪs; NAmE ; ˈgreɪtɪs/ adverb
done or given without having to be paid for
SYN free of charge :
I knew his help wouldn't be given gratis.
► gra·tis adjective :
a gratis copy of a book
••
WORD ORIGIN
late Middle English : from Latin , contraction of gratiis as a kindness, from gratia grace, kindness.