A harmonic balancer sounds like a crucial part on a spaceship in some pulpy 1950s sci-fi story, or something you need so you can play music with hobos when you're ridin' the rails. However, it's actually an important part on your engine that helps your crankshaft last as long as possible.
U.S. National Library of Medicine (5.00 / 1 vote) Rate this definition: Mitochondria. Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae.
(plural mitochondria) (cytology) A spherical or ovoid organelle found in the cytoplasm of eukaryotic cells, contains genetic material separate from that of the host; it is responsible for the conversion of food to usable energy in the form of ATP.