Form of bow used to fire arrows with a bow much smaller than the traditional *longbow, being drawn or cranked by a handle with a trigger release; it was so called because it somewhat resembled a cross (probably the single most potent image of the time). The crossbow was easier to handle than a longbow because of its use of a crank. However, this was also its great disadvantage, since it took longer to reload than the longbow. The crossbow had a range of up to 250 yards and was used best at relatively close quarters. However, in the mid-15c a steel crossbow emerged, with a range of up to 450 yards, and powerful enough to unhorse an armoured knight. The user was known as an *'arbalester'. -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.