The Collaborative International Dictionary of English v.0.48:
Arca \Arca\ n. 1. 1 the type genus of the family Arcidae, including ark shells and blood clams. Syn: genus Arca. [WordNet 1.5]WordNet (r) 3.0 (2006):
Arca n 1: type genus of the family Arcidae: ark shells and blood clams [syn: Arca, genus Arca]V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
ARCA Advanced RISC Computing Architecture (ACE, RISC)