The Collaborative International Dictionary of English v.0.48:
Heimdall \Heimdall\ n. Same as Heimdal. Syn: Heimdal, Heimdallr. [WordNet 1.5]WordNet (r) 3.0 (2006):
Heimdall n 1: (Norse mythology) god of dawn and light; guardian of Asgard [syn: Heimdall, Heimdal, Heimdallr]