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)