The noun dinner has 2 senses (first 2 from tagged texts)
1. (25) dinner -- (the main meal of the day served in the evening or at midday; "dinner will be at 8"; "on Sundays they had a large dinner when they returned from church")
2. (5) dinner, dinner party -- (a party of people assembled to have dinner together; "guests should never be late to a dinner party")