[f. SUM v.1 + -ING2.] That sums or sums up; summarizing.

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1860.  I. Burns, Pastor of Kilsyth, 248. The great and summing evil … is just ‘the quenching the spirit.’

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1887.  Homeop. World, 1 Nov., 501. The president made a few summing-up remarks.

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