gelidium
noun
ge·lid·i·um
jəˈlidēəm
1
capitalized : a genus of red algae (family Gelidiaceae) having cartilaginous terete or compressed much-branched fronds and cystocarps immersed in swollen branchlets and being important sources of agar see gelidiales
2
plural -s : any alga of the genus Gelidium
Word History
Etymology
New Latin, from Latin gelidus (influenced in meaning by Latin gelare to freeze, congeal) + New Latin -ium; from the fact that the plants are boiled down to make a jelly