The aklys ( Latinaclys, Greekagkulis) was a Roman javelin measuring approximately 2 m (79 in, 6.6 ft) in length, thrown with the aid of a leather strap or amentum, similar to a Swiss arrow. Every soldier was issued at least two. The origin is believed to trace back to the sixth century B.C.E. Oscan tribe in Italy.
The term also applies to a small mace or club equipped with spikes, attached to one arm of the wielder by a strap of adjustable length to enable the weapon to be retrieved after it had been hurled at an enemy. Its use probably goes back to the Osci tribe of southern Italy. The weapon is also described as a dart and as a throwing stick or boomerang.