The Collaborative International Dictionary
Interambulacrum
Interambulacrum \In`ter*am`bu*la"crum\, n.; pl. L. Interambulacra, E. Interambulacrums. (Zo["o]l.) In echinoderms, one of the areas or zones intervening between two ambulacra. See Illust. of Ambulacrum.
Wiktionary
interambulacrum
n. (context zoology English) In echinoderms, one of the areas or zones intervening between two ambulacrum.