Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Sperm \Sperm\, n.[Contr. fr. spermaceti.] Spermaceti.
Sperm oil, a fatty oil found as a liquid, with spermaceti, in the head cavities of the sperm whale.
Sperm whale. (Zo["o]l.) See in the Vocabulary.
Sperm whale \Sperm" whale`\ (Zo["o]l.) A very large toothed whale ( Physeter macrocephalus), having a head of enormous size. The upper jaw is destitute of teeth. In the upper part of the head, above the skull, there is a large cavity, or case, filled with oil and spermaceti. This whale sometimes grows to the length of more than eighty feet. It is found in the warmer parts of all the oceans. Called also cachalot, and spermaceti whale.
Pygmy sperm whale (Zo["o]l.), a small whale ( Kogia breviceps), seldom twenty feet long, native of tropical seas, but occasionally found on the American coast. Called also snub-nosed cachalot.
Sperm-whale porpoise (Zo["o]l.), a toothed cetacean ( Hypero["o]don bidens), found on both sides of the Atlantic and valued for its oil. The adult becomes about twenty-five feet long, and its head is very large and thick. Called also bottle-nosed whale.
Wiktionary
n. A whale (''Physeter macrocephalus''), the largest of the toothed whales.
WordNet
n. large whale with a large cavity in the head containing spermaceti and oil; also a source of ambergris [syn: cachalot, black whale, Physeter catodon]
Wikipedia
The sperm whale (Physeter macrocephalus), or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.
Mature males average in length but some may reach , with the head representing up to one-third of the animal's length. Plunging to , it is the second deepest diving mammal, following only the Cuvier's beaked whale. The sperm whale's clicking vocalization, a form of echolocation and communication, may be as loud as 230 decibels (re 1 µPa at 1 m) underwater. It has the largest brain of any animal on Earth, more than five times heavier than a human's. Sperm whales can live for more than 60 years.
The sperm whale can be found anywhere in the open ocean. Females and young males live together in groups while mature males live solitary lives outside of the mating season. The females cooperate to protect and nurse their young. Females give birth every four to twenty years, and care for the calves for more than a decade. A mature sperm whale has few natural predators, although calves and weakened adults are sometimes killed by pods of orcas.
From the early eighteenth century through the late 20th, the species was a prime target of whalers. The head of the whale contains a liquid wax called spermaceti, from which the whale derives its name. Spermaceti was used in lubricants, oil lamps, and candles. Ambergris, a waste product from its digestive system, is still used as a fixative in perfumes. Occasionally the sperm whale's great size allowed it to defend itself effectively against whalers. The species is now protected by a whaling moratorium, and is currently listed as vulnerable by the International Union for the Conservation of Nature and Natural Resources (IUCN).