Definition of coelacanth - a large bony marine fish with a
three-lobed tail fin and fleshy pectoral fins. It was known only
from fossils until one was found alive in 1938; since then
others have been found near the Comoro Islands in the Indian
Ocean and off Sulawesi, Indonesia. - Latimeria chalumnae, family
Latimeriidae (or Coelacanthidae), subclass Crossopterygii mid
19th century: from modern Latin Coelacanthus (genus name), from
Greek koilos 'hollow' + akantha 'spine' (its fins have hollow
spines)