This is the 3814th most frequent Japanese word.
みかん
Mandarin orange.
In this sentence, 'みかん' refers to the fruit mandarin, which is being eaten.
私は毎朝みかんを食べます。
I eat mandarins every morning.
Here, 'みかん' is associated with the mandarin fruit that grows on a tree.
庭のみかんの木にたくさん実がなった。
The mandarin tree in the garden bore a lot of fruit.
In this usage, 'みかん' refers to the color similar to that of mandarins, describing the sunset.