Webster's Revised Unabridged Dictionary · 1913

Picnic

Picnic , noun

[Compare French piquenique. See Pick, v., and compare Knickknack.]

Formerly, an entertainment at which each person contributed some dish to a common table; now, an excursion or pleasure party in which the members partake of a collation or repast (usually in the open air, and from food carried by themselves).

Picnic , intransitive verb

To go on a picnic, or pleasure excursion; to eat in public fashion.