nematocyst

英 [nɪ'mætə(ʊ)sɪst; 'nemət-] 美[nɪ'mætəsɪst]

nematocyst (n.): 1875, from nemato-, comb. form of Greek nema, nematos "thread" (genitive nematos), from stem of nein "to spin" (see needle (n.)) + cyst.