armed conflict between opposing forces: the condition of being at war, or a specific battle
The word covers the full range of what English distributes between "war" and "battle." It names the state of being at war (the long conflict between two kingdoms), the activity of fighting (the day a king marches out), and the single encounter (the clash where the battle turns and men fall). All three run together in the original because the same phenomenon, armies in armed confrontation, gives rise to all of them.
The word regularly describes a person's identity and occupation: a man of war, someone trained for war, men who go out to fight. It marks a season in a community's life ("there was war between them all his days"), and it names the sphere God sometimes occupies ("the LORD is a man of war," Exodus 15:3). It also appears in Wisdom texts as something to be managed with counsel and strategy, pointing to a more institutional sense, warfare as a craft that requires thought, not just force.
Because one Hebrew noun covers territory that English distributes across several words, translators have many options: battle, war, warfare, fighting, combat. None of these is wrong in a given passage, but none fully captures the word on its own.