The Collaborative International Dictionary of English v.0.48:
Internally \In*ter"nal*ly\, adv. 1. Inwardly; within the enveloping surface, or the boundary of a thing; within the body; beneath the surface. [1913 Webster] 2. Hence: Mentally; spiritually. --Jer. Taylor. [1913 Webster]WordNet (r) 3.0 (2006):
internally adv 1: on or from the inside; "an internally controlled environment" [ant: externally]