D defs.my
Entry 4 senses Webster, 1913

Retardation

/rē′tär-dā′shən/ · Re·tar·da·tion · IPA /ˌɹi.tɑɹˈdeɪ̯.ʃən/
01 n. The act of retarding; hindrance; the act of delaying; as, the retardation of the motion of a ship; -- opposed to acceleration.
  1. 1.
    The act of retarding; hindrance; the act of delaying; as, the retardation of the motion of a ship; -- opposed to acceleration.
    “The retardations of our fluent motion.” — De Quinsey.
  2. 2.
    That which retards; an obstacle; an obstruction.
    “Hills, sloughs, and other terrestrial retardations.” Sir W. Scott.
  3. 3.
    The keeping back of an approaching consonant chord by prolonging one or more tones of a previous chord into the intermediate chord which follows; -- differing from suspension by resolving upwards instead of downwards.(Mus.)
  4. 4.
    The extent to which anything is retarded; the amount of retarding or delay.
Phrases & compounds
Retardation of the tide — The lunitidal interval, or the hour angle of the moon at the time of high tide any port; the interval between the transit of the moon and the time of high tide next following