The word "pikn" The origin of the word pikn in the etymological online dictionary of Krylov G. A.
From French paradise 1820; it. picniere borrowing. from it., from where french.. picсerie < лат. picis «пеструха» (в смысле «пестрая изгородь»); см. Писсарро, Пиэль.
Etymology
As with many modern words, the word "picnic" is borrowed through the German language, although this is a rather interesting phenomenon - the sources of all languages interact in one way or another in different areas. However, you can also find reverse borrowing: English. picnic; German Picknick; Polish piętnik