The Collaborative International Dictionary of English v.0.48:
Roily \Roil"y\, a. Turbid; as, roily water. [1913 Webster]WordNet (r) 3.0 (2006):
roily adj 1: (of a liquid) agitated vigorously; in a state of turbulence; "the river's roiling current"; "turbulent rapids" [syn: churning, roiling, roiled, roily, turbulent]