battalia

Etymology

Borrowed from Late Latin battālia, variant of battuālia (“military exercises”), from Latin battuō (“to strike, beat”), from Gaulish. Doublet of battle.

Why this word is great

BATTALIA — [Noun] The order of battle or arrangement of troops ready for action; also, the main body of an army in battle array. From Late Latin battālia, a variant of battuālia ("military exercises"), from Latin battuō ("to strike, beat"), of Gaulish origin. Doublet of battle. Unlike "battalion" (which denotes a specific military unit) or "vanguard" (which signifies the spearhead of an advance), battalia is the deliberate geometry of force, the spine of an army poised to break or be broken. It is the silent bristle of pikes at dawn, the dust rising in disciplined clouds behind marching squares, the terrible stillness before the trumpet's cry—the moment when order holds, just barely, against the coming storm.

noun

Order of battle; disposition or arrangement of troops or of a naval force, ready for action.“[…]but we find, by a sad experience, that few questions are well stated; and when they are, they are not consented to; and when they are agreed on by both sides that they are well stated, it is nothing else but a drawing up the armies in battalia with great skill and discipline; the next thing they do is, they thrust their swords into one another's sides.”
An army in battle array; also, the main battalia or body of the army, as distinct from the vanguard and rear.“Why, our battalia trebles that account”