a review or recapitulation of previously stated facts or statements, often with a final conclusion or conclusions drawn from them.
Law. the final arguments of opposing attorneys before a case goes to the jury.
Physiology. the arousal of impulses by a rapid succession of stimuli, carried either by separate sensory neurons (spatial summation) or by the same sensory neuron (temporal summation).
Origin of summation
1750–60; < Medieval Latinsummātiōn- (stem of summātiō), equivalent to summāt(us) (past participle of summāre to sum; see -ate1) + -iōn--ion
1760, from Modern Latin summationem (nominative summatio) "an adding up," from Late Latin summatus, past participle of summare "to sum up," from Latin summa (see sum).