Gratis is an adverb which means free, without charge. Gratis stems from the mid-fifteenth century, from a contraction of the Latin word gratiis meaning for thanks, without recompense, for nothing.
Gratuitous is an adjective which describes something done for no good reason, an action which is uncalled for. The adverb form is gratuitously and the noun form is gratuitousness. In 1650, gratuitous meant done without pay, voluntary. The dictionary gives this definition as a secondary use, though one rarely hears gratuitous used this way. The favored meaning of gratuitous, uncalled for, first appeared in the 1690s.
A gratuity is an extra remuneration given for services rendered, a tip. Gratuity describes something given without obligation. The word gratuity first appears in the early fourteenth century from the French, gratuite, meaning graciousness.
There is no question — tickets to the Public Theater’s Shakespeare in the Park are supposed to be gratis, but that’s not stopping scalpers from selling them for upwards of $400. (The New York Post)
But the suspicion that they may, in the future, come very cheap indeed to the point of being distributed gratis was reinforced by last week’s revelation that stand-up comedians are begging the Arts Council to reverse its de facto ban on supporting comedy in the same way that it subsidises other art forms. (The Independent)
“…And attempts now at rewriting history, that this was all, in some way, facilitated by the opposition, is simply a piece of gratuitous aggrandisement.” (Financial Review)
To be abundantly clear, The Scrapbook abhors the illegal or gratuitous killing of animals. (The Weekly Standard)
“It’s printed on every receipt all day long that there may be an 18 percent gratuity for parties of six or more and after 10 p.m.,” Stephens said. (The Fayetteville Observer)
“If you are punished in a corruption case, you will be only jailed and asked to return the money while in a gratuity case, your wealth will be confiscated and you can be charged for money laundering,” he said. (Jakarta Post)