cumulus \KYOO-myuh-luhs\ , noun:
1. A heap; pile.
2. A cloud of a class characterized by dense individual elements in the form of puffs, mounds, or towers, with flat bases and tops that often resemble cauliflower.

While the 2011 Tide defense was one of the most dominant units in the history of college football, early season efforts seemed undisciplined and mistake filled compared to the latter part of the schedule. I suspect a season long cumulus of experience played a large part in the difference.