This is the 3147th most frequent Japanese word.
剣道
Kendo: A traditional Japanese martial art of fencing with bamboo swords.
剣道 is used as the subject of the sentence, indicating the activity or martial art the person enjoys.
私は剣道が大好きです。
I love Kendo.
剣道 is the object of the verb 学ぶ (to learn), indicating the discipline he is studying.
彼は剣道を学んでいます。
He is learning Kendo.
剣道 is part of a possessive construction with 試合 (match), specifying the type of competition being referred to.