This is the 246th most frequent Russian word.
боевых
The Russian word "боевых" means "combat" or "military" (genitive or plural form, depending on context).
The word 'боевых' here is used as an adjective modifying 'искусств' (arts), describing the type of arts as martial.
Он посещал курсы по изучению боевых искусств.
He attended courses for learning martial arts.
The word 'боевых' functions as an adjective describing 'действий' (actions), indicating that the actions are related to combat.
Солдаты готовили всё необходимое для проведения боевых действий.
The soldiers prepared everything necessary for conducting combat operations.
Here, 'боевых' acts as a descriptive adjective for 'технологий' (technologies), signifying that these technologies are associated with battles.