ambulacrum
Concise Oxford English Dictionary © 2008 Oxford University Press:
ambulacrum /ˌambjʊˈleɪkrəm, -ˈlakrəm/
▶noun (pl. ambulacra /-ˈleɪkrə, -ˈlakrə/) Zoology (in an echinoderm) each of the radially arranged bands through which the double rows of tube feet protrude.
– derivatives
ambulacral adjective.
ambulacral adjective.
– origin C19: L., ‘avenue’, from ambulare ‘to walk’.
'ambulacrum' also found in these Oxford entries:

