It´s the "delay" of the primary weapon, additionaly created to the animation delay that is not affected by the stats, but by the unit model, afaik.
In your example "spear" is a primary weapon, while sword would be the secondary; to indicate the advantage of the sword vs. spear = the faster attack, the value 180 makes the spear slow/less frequent in attack compared to the sword, but mostly coupled with higher lethality ( 0.38 the spear vs. 0.13/0.11 ( ap mostly ) for the sword.