noun
headgear; protective headgear
Refers to protective headgear, especially in sports such as boxing, martial arts, or cycling.
ボクシングの試合ではヘッドギアを着用する。
In boxing matches, they wear headgear.
自転車に乗るときはヘッドギアをかぶったほうが安全だ。
It's safer to wear a helmet when riding a bicycle.