American Heritage® Dictionary of the English Language, Fourth Edition
- n. The main fin located on the back of fishes and certain marine mammals.
- n. unpaired median fin on the backs of fishes and some other aquatic vertebrates that help to maintain balance
“Fritz was unanimously voted her rightful owner, but before his mother would hear of his entering the frail-looking skiff she declared that she must contrive a swimming-dress, so that ‘should his boat receive a puncture from a sharp rock or the dorsal fin of a fish and collapse, he might yet have a chance of saving his life’.”
“And a new kind of pride-filled emotion welled up in Gaius Marius as he continued to watch that lictorial dorsal fin cleave the ocean of Roman lowly — pride in the old ways, the customs and traditions of six hundred and fifty-four years, so powerful still that it could turn a tide greater than the German invasion with no more effort than the shouldering of a few bundles of sticks.”
“About a hundred feet back from the bows the slender yet massive conning tower reared over twenty feet above the deck, for all the world like the great dorsal fin of some monstrous shark; halfway up the sides of the conning tower and thrust out stubbily at right angles were the swept-back auxiliary diving planes of the submarine.”
“A huge dorsal fin rose up like a long-lost island from beneath dark waves.”
Looking for tweets for dorsal fin.