long-armed squid noun2 •A species of chiroteuthid squid, Chiroteuthis veranii, having exceptionally long arms, and a total adult length of 130 cm (51 in). •Synonym of bigfin squid (“Any member of the genus Magnapinna of rarely seen squid, characterized by extremely long arms and tentacles, and being the only squid known to inhabit the hadal zone of the ocean.”). formslong-armed squids