From the Urban Dictionary

For those of you who doubted me, I am providing you definitions for the word "assload." It's even in the Bible!

1. ASSLOAD

More than a lot but less than a shitload Man, I have an assload of reading for history tonight.

2. ASSLOAD

The burden that can be borne by one's ass (Equus asinus)

And he said unto his sons, Saddle me the ass. So they saddled him the ass: and he rode thereon, and was an assload. (Kings 1, 13:13)