The Collaborative International Dictionary of English v.0.48:
Overcloud \O`ver*cloud"\, v. t. To cover or overspread with clouds; to becloud; to overcast. [1913 Webster]WordNet (r) 3.0 (2006):
overcloud v 1: become covered with clouds; "The sky clouded over" [syn: overcloud, cloud over, cloud up] 2: make obscure or unclear; "The distinction was obscured" [syn: obscure, bedim, overcloud]