[3] The acinaces is typically 40–60 cm (16–24 in) in length and double-edged,[3] and although there is no universal design, the guard may be lobed[4] with the hilt resembling that of a bollock dagger, or the pommel may be split[5] or of the "antenna" type.
[6] The scabbard – as much as anything else – defines the acinaces, and usually has a large decorative mount near the opening, allowing it to be suspended from a belt on the wearer's right side.
Because of this, authors writing in Latin throughout history tended to equate the word with whatever type of weapon the contemporary Persians were using.
Ancient Persian art typically shows the king's bodyguards and important nobles wearing ornate diagonal daggers.
A very revealing passage is found in Josephus' Jewish Antiquities 20.186, where the weapons used by the sicarii are described: And the so-called sicarii, which were a type of bandit, were at that time reaching their greatest number, making use of small swords, which were like the Persian acinaces in respect to their size, but curved like the Roman sica, which is where these bandits got their name.This also seems to indicate that it is the dagger which is properly called the acinaces though there are those[who?]