word-forming element meaning "battle, war, contest, fighting, warfare," from Latinized form of Greek -makhia, from makhē "a battle, fight," related to makhesthai "to fight." Beekes suspects it is from an isolated root, perhaps Pre-Greek: "In the domain of fighting and battle, old inherited expressions can hardly be expected."
"a champion, one who fights on behalf of another," by 1905, from Latinized form of Greek promakhos "a deity (especially Athene or Apollo) who fights before some person, army, or state as a protector or guardian," from pro "before" (see pro-) + makhesthai "to fight" (see -machy). The word is attested from 1871 in reference to the colossal bronze statue of Athene Promachos that stood in the Athenian citadel.
1620s, "sham-fight for exercise or practice," from Latinized form of Greek skiamakhia "shadow-fighting, a sham fight," from skia "shade, shadow" (see Ascians) + makhē "battle" (see -machy). The notion in the Greek word is said sometimes to be "fighting in the shade" (i.e. practicing in school; ancient teachers taught in shaded public places such as porches and groves), but it seems also to have had a sense of "fighting with shadows, shadow-boxing." In English, often figurative, of futile combat with an imaginary enemy.