from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Relating to, having, or being a tail fin in which the upper lobe is larger than the lower and the vertebral column extends into the upper lobe, as in sharks.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of a fish's tail, such that the vertebral column bends and extends upwards into the upper lobe of the tail, making it larger than the lower lobe; as in sharks, rays, and skates.
from the GNU version of the Collaborative International Dictionary of English
- adj. Having the vertebral column evidently continued into the upper lobe of the tail, which is usually longer than the lower one, as in sharks.
from The Century Dictionary and Cyclopedia
- In ichthyology, having an unequally divided tail or caudal fin. Contrasted with homocercal.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. possessing a tail with the upper lobe larger than the lower and with the vertebral column prolonged into the upper lobe
hetero- + Greek kerkos, tail + -al1.(American Heritage® Dictionary of the English Language, Fourth Edition)