Autolyse is a bread-making rest in which flour and water are mixed just until combined and left before kneading. Hydration and enzyme activity make the dough easier to stretch and can reduce mixing. In a strict autolyse, salt and the yeast or starter are added afterward; a rest that includes starter is a variation.
This is different from yeast autolysis, the breakdown of yeast cells associated with lees aging and fermentation.
Reference: Further reading.