Picnic comes to us from the French pique-nique. The original French meaning, first appearing in 1694 in the form repas à piquenique, referred to a meal where everyone contributed either food or money, a pot-luck meal. In modern French usage, the term has adopted the English sense of a meal eaten as part of an outing of some sort.
The first element in the French term, pique, is similar to the English pick. Both can mean to eat, in particular to eat in small, dainty mouthfuls. Nique originally had a meaning of nothing and later came to be used to mean a small coin. Undoubtedly chosen because it is reduplicative with pique, it can be interpreted to mean a trifle. So a picnic is a meal of small items or delicacies.
Picnic makes its English appearance in 1748 in a letter by the 4th Earl of Chesterfield:
I like the description of your pic-nic, where I take it for granted that your cards are only to break the formality of a circle.
But English use of picnic did not become widespread until around 1800.
Folklore has the origin of this word as lynching party for blacks in the American South, deriving from the phrase pick an nigger. This is absolutely incorrect. The word’s origin is in Europe, has no racial overtones whatsoever, and, as we have seen, long predates the practice of lynching blacks.
(Source: Oxford English Dictionary, 3rd Edition)
Copyright 1997-2015, by David Wilton