Although the family name of Belcher is a prominent one in English and American history, it is actually Old French in origin. The ancestor of the Belcher family came to England from France, as part of William the Conqueror's army that came to England in the Norman Conquest of 1066 A.D.
(Microbiology) any of several viruses whose genetic specification is encoded in RNA rather than DNA and that are able to reverse the normal flow of genetic information from DNA to RNA by transcribing RNA into DNA: many retroviruses are known to cause cancer in animals.
Meaning and definition of retrovirus : An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome, an important class of cancer-causing viruses.eaning and definition of retrovirus : An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome, an important class of cancer-causing viruses.