This is the 5606th most frequent Japanese word.
こぶし
"こぶし" can mean "fist" or refer to the "magnolia tree" depending on context.
In this context,
音楽に合わせてリズムを取りながらこぶしを効かせた歌声が響いた。
The singer's voice harmonized with the rhythm to emphasize kobushi in the music.
In this sentence,
彼は怒りでこぶしを握った。
He clenched his fist in anger.
Here,