You learn what letter your blood type is (A, B, AB, and O). You also learn what your Rhesus, or RH, factor is. Your blood is either RH+, meaning the blood has the RH factor, or RH-, meaning the RH factor is not in your blood.he c, e, and d genes are negative RH genes; meaning there is no RH factor in the blood. Research shows only the âDâ gene causes sensitivity issues, so itâs the D gene that is of concern during your pregnancy. Thatâs why some care providers call the RH factor RH (D) positive or RH (D) negative.
Definition of RETARDATION. 1. : an act or instance of retarding. 2. : the extent to which something is retarded. 3. : a musical suspension; specifically: one that resolves upward. 4. a: an abnormal slowness of thought or action; especially: mental retardation b: slowness in development or progress.
Word Origin and History for retard Expand. v. late 15c., make slow or slower, from French retarder restrain, hold (someone) back, keep (someone from doing something); come to a stop (13c.) or directly from Latin retardare make slow, delay, keep back, hinder (see retardation). Related: Retarded; retarding. The noun is recorded from 1788 in the sense retardation, delay; from 1970 in offensive meaning retarded person, originally American English, with accent on first syllable. Other words used for one who is mentally retarded include retardate (1956), retardee (1971).