Concentration
Focus
noun, verbal noun
When you collect to the middle of yourself, you are collecting towards your brain. All energy is going towards there, massing up in the middle, giving you extreme concentration and focus.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
試験の間は、集中しましょう。
Let's concentrate during the exam.
パパがゲームに集中している時は、話しかけない方がいいよ。
You should not talk to Dad when he is concentrated in a game.
ミーティングに集中しすぎて、朝ごはんをまだ食べてないことを今思い出しました。
I was too focused on the meeting that I've just remembered that I haven't had my breakfast yet.
日本は、東京などの大きな町に人口が集中しています。
In Japan, the population is concentrated in large cities such as Tokyo.