This is the 5718th most frequent Japanese word.
ちなむ
"To be associated with" or "to be related to."
The word "ちなむ" in this context means 'associating with' or 'related to' a particular theme, which is 'autumn' for the dish.
その料理は秋にちなむ具材が使われています。
That dish uses ingredients associated with autumn.
Here, "ちなむ" indicates that the patterns in the design are inspired by or drawn from traditional culture.
彼のデザインは伝統文化にちなむ模様が特徴です。
His design is characterized by patterns inspired by traditional culture.
In this sentence, "ちなむ" is used to suggest a connection or association with a historical event for the festival.