small densely furred aquatic monotreme of Australia and Tasmania having a broad bill and tail and webbed feet; only species in the family Ornithorhynchidae
any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk
graceful Old World ruminant with long legs and horns directed upward and backward; includes gazelles; springboks; impalas; addax; gerenuks; blackbucks; dik-diks
any of various rotating shafts that serve as axes for larger rotating parts
(biology) tiny fibers that are seen in cell division; the fibers radiate from two poles and meet at the equator in the middle; "chromosomes are distributed by spindles in mitosis and meiosis"