It is usually known as a battle.
That would be a battle.
for avoid a battle between two armies.
Allied armies are Armies from different countries that are working on the same side. Two or more countries may come together to fight a common enemy, this would make them allied armies.
A fight to the finish
it were between two
The area between the two armies facing each other is often called by Americans as "no-man's land".
We had fought Japan because they had invaded France
A duel is a fight between two people
A duel is a fight between two people
No, frontier is any unexplored area which is why space may be the final "frontier".
an Adder (snake) bit one of Arthurs men, when he took out his sword and killed the snake he men of Mordreds army thought he mean to fight. :)
There is no specific term for when two gay men fight. It would be called a fight or altercation, just like any other disagreement between individuals. It is important to avoid using derogatory language or making assumptions based on someone's sexual orientation.