This is the 1427th most frequent Japanese word.
敵
Enemy.
The word '敵' is used to describe a foe or adversary in a combat or conflict context.
敵は城に近づいている。
The enemy is approaching the castle.
Here, '敵' indicates a personal rival or someone whom the speaker competes with.
彼は私の最大の敵だ。
He is my greatest rival.
In this sentence, '敵' refers to the general concept of opposition as opposed to '味方', meaning allies.