more than an assload but still less than a fuckton.

In Software Engineering, an IEEE recognized standardized unit. The number of instances of a problem that must occur in an area/component that falls outside your area of ownership - usually 1 such occurrence qualifies as a shitload. If the problem occurs in your own area, the multiplier is 100x as any instance is obviously warranted and is merely providing good data.

Many, as in, more than a few in quantity.

A corruption of the term "shipload" of antiquity, as described the massive cargoes brought into harbor by sea-faring ships. Through association to the perjorative "shit" (itself a corruption of "shite"), the terms "fuck load", "ass load", and "butt load" were all created, the user, unaware of the origins of the term, substituting one curse word interchangeably for another. Over time, the second half of the expression also came to be substituted, most often in cases where "ton" was inserted for "load", whilst still maintaining the previously-replaced derisories as variations of the newly-coined phrase.

In its "proper" form, the phrase would be hyphenated and expressed as a linkage between two words to describe a third, correlated concept (i.e. "shit-load")

Shitloads is "LONG" for lots.

(Colloquial) The amount of cow manure that will fit in the bed of a 3/4 ton pickup. For fresh, wet, stinking manure, this would be 750 pounds. For dry manure, something less, perhaps 500 pounds.

10% more than you can carry at one time.