\"1748 (in Chesterfield's \"Letters\"), but rare before c.1800 as an Eng. institution, from Fr. piquenique (1692), perhaps a reduplication of piquer \"to pick, peck,\" from O.Fr. (see
pike (2)), or the second element may be nique \"worthless thing,\" from a Gmc. source. Originally a fashionable pot-luck social affair, not necessarily out of doors. Figurative sense of \"something easy\" is from 1886.\"