Picnicker
/ˈpɪknɪkər/
Definition 1 of 1
Pro Tip 1/3Activity Context
The term picnicker indicates someone engaging in a casual outdoor dining activity, often in a scenic or park setting. 
We saw a group of picnickers by the lake enjoying the sunny weather.
Pro Tip 2/3Family Friendly
The word picnicker frequently implies a family or social connection, portraying a group-oriented person. 
Every summer, she becomes an enthusiastic picnicker, hosting family gatherings at the park.
Pro Tip 3/3Leisurely Tone
Using picnicker suggests leisure and relaxation; it's not associated with formal dining experiences. 
As a picnicker, he preferred casual picnics over dining in upscale restaurants.