the arithmetic operation of summing; calculating the sum of two or more numbers; "the summation of four and three gives seven"; "four plus three equals seven"
a concluding summary (as in presenting a case before a law court)
(physiology) the process whereby multiple stimuli can produce a response (in a muscle or nerve or other part) that one stimulus alone does not produce
the erosive process of washing away soil or gravel by water (as from a roadway); "from the house they watched the washout of their newly seeded lawn by the water"
the channel or break produced by erosion of relatively soft soil by water; "it was several days after the storm before they could repair the washout and open the road"