from the GNU version of the Collaborative International Dictionary of English
- n. the interval between the transit of the moon at which a tide originates and the appearance of the tide itself. It is found, in general, that any particular tide is not principally due to the moon's transit immediately proceeding, but to a transit which has occured some time before, and which is said to correspond to it. The retard of the tide is thus distinguished from the lunitidal interval. See under Retardation.
Sorry, no etymologies found.