The Collaborative International Dictionary of English v.0.48:
Rigidly \Rig"id*ly\, v. In a rigid manner; stiffly. [1913 Webster]WordNet (r) 3.0 (2006):
rigidly adv 1: in a rigid manner; "the body was rigidly erect"; "he sat bolt upright" [syn: rigidly, stiffly, bolt]